When determining the sample size for a proportion for a given level of confidence and sampling error, the closer to 0.50 that ? is estimated to be, the sample size required ________.
larger
The width of a confidence interval estimate for a proportion will be
narrower for 90% confidence than for 95% confidence.
A 99% confidence interval estimate can be interpreted to mean that
both of the above
If you were constructing a 99% confidence interval of the population mean based on a sample of n = 25, where the standard deviation of the sample s = 0.05, the critical value of t will be
2.7970.
Which of the following is NOT true about the Student's t distribution?
It is used to construct confidence intervals for the population mean when the population standard deviation is known.
Suppose a 95% confidence interval for ? turns out to be (1,000, 2,100). Give a definition of what it means to be "95% confident" as an inference.
In repeated sampling, 95% of the intervals constructed would contain the population mean.
Suppose a 95% confidence interval for has been constructed. If it is decided to take a larger sample and to decrease the confidence level of the interval, then the resulting interval width would . (Assume that the sample statistics gathered would not chan
be narrower than the current interval width
In the construction of confidence intervals, if all other quantities are unchanged, an increase in the sample size will lead to an interval that's..
narrower
A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following res
A t distribution with 14 degrees of freedom
A major department store chain is interested in estimating the average amount its credit card customers spent on their first visit to the chain's new store in the mall. Fifteen credit card accounts were randomly sampled and analyzed with the following res
$50.50 +- $11.08
Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much of this money is put into a fund called an endowment, and the college spends only the interest earned by the fund. A recent surv
$180.975
Private colleges and universities rely on money contributed by individuals and corporations for their operating expenses. Much of this money is put into a fund called an endowment, and the college spends only the interest earned by the fund. A recent surv
$180.975 � $119.586
A university system enrolling hundreds of thousands of students is considering a change in the way students pay for their education. Currently, the students pay $55 per credit hour. The university system administrators are contemplating charging each stud
n = 2033
As an aid to the establishment of personnel requirements, the director of a hospital wishes to estimate the mean number of people who are admitted to the emergency room during a 24-hour period. The director randomly selects 64 different 24-hour periods an
19.8 � 1.249
As an aid to the establishment of personnel requirements, the director of a hospital wishes to estimate the mean number of people who are admitted to the emergency room during a 24-hour period. The director randomly selects 64 different 24-hour periods an
n = 166
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial a
0.59 � 0.057 or 0.533 ? (Pie symbol) ? 0.647
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial a
We are 95% confident that the true proportion of all students receiving financial aid is between 0.52 and 0.66.
A university dean is interested in determining the proportion of students who receive some sort of financial aid. Rather than examine the records for all students, the dean randomly selects 200 students and finds that 118 of them are receiving financial a
n = 1,784
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What is the upper end point in a 9
$15,364
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What is the width of the 90% confi
$465.23
An economist is interested in studying the incomes of consumers in a particular region. The population standard deviation is known to be $1,000. A random sample of 50 individuals resulted in an average income of $15,000. What total sample size would the e
n = 1537
The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. What is an efficient, u
830
The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. If the head librarian k
It cannot be determined from the information given.
The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. If the head librarian k
11
The head librarian at the Library of Congress has asked her assistant for an interval estimate of the mean number of books checked out each day. The assistant provides the following interval estimate: from 740 to 920 books per day. If the head librarian k
99.7%
True or False: A race car driver tested his car for time from 0 to 60 mph, and in 20 tests obtained an average of 4.85 seconds with a standard deviation of 1.47 seconds. A 95% confidence interval for the 0 to 60 time is 4.52 seconds to 5.18 seconds.
False
Which of the following would be an appropriate null hypothesis?
The mean of a population is equal to 55.
Which of the following would be an appropriate null hypothesis?
The population proportion is no less than 0.65.
Which of the following would be an appropriate alternative hypothesis?
The mean of a population is greater than 55.
Which of the following would be an appropriate alternative hypothesis?
The population proportion is less than 0.65.
The power of a test is measured by its capability of
rejecting a null hypothesis that is false.
If we are performing a two-tailed test of whether ?= 100, the probability of detecting a shift of the mean to 105 will be ________ the probability of detecting a shift of the mean to 110
less than
True or False: For a given level of significance, if the sample size is increased, the power of the test will increase
True
If an economist wishes to determine whether there is evidence that the average family income in a community exceeds $25,000, what kind of test should be used?
A one-tailed test should be utilized
If an economist wishes to determine whether there is evidence that the average family income in a community equals $25,000. What kind of test should be used?
A two-tailed test should be utilized
How many Kleenex should the Kimberly Clark Corporation package of tissues contain? Researchers determined that 60 tissues is the average number of tissues used during a cold. Suppose a random sample of 100 Kleenex users yielded the following data on the n
-3.634
For a given sample size n, if the level of significance is decreased, the power of the test will:
decrease
A hypothesis test is to be conducted using an alpha = .05 level. This means:
there is a maximum 5 percent chance that a true null hypothesis will be rejected.
If the p value is less than ? in a two-tailed test then:
the null hypothesis should be rejected.
A contract calls for the mean diameter of a cylinder to be 1.50 inches. As a quality check, each day a random sample of n = 36 cylinders is selected and the diameters are measured. Assuming that the population standard deviation is thought to be 0.10 inch
Can't be determined without knowing the "true" population mean
An assumption made about the value of a population parameter is called a
Hypothesis
In hypothesis testing, the tentative assumption about the population parameter is
the null hypothesis
For a lower tail test, the p-value is the probability of obtaining a value for the test statistic
at least as small as that provided by the sample
The p-value is a probability that measures the support (or lack of support) for the
null hypothesis
The p-value
is a probability
For a two-tail test, the p-value is the probability of obtaining a value for the test statistic as
unlikely as that provided by the sample
In hypothesis testing if the null hypothesis is rejected,
the alternative hypothesis is true
The power curve provides the probability of
correctly rejecting the null hypothesis
The level of significance in hypothesis testing is the probability of
rejecting a true null hypothesis
The level of significance
is (1 - confidence level)
In hypothesis testing if the null hypothesis has been rejected when the alternative hypothesis has been true,
the correct decision has been made
When the following hypotheses are being tested at a level of significance of ?
H0: ? <= 100
Ha: ? < 100
the null hypothesis will be rejected if the p-value is
?
When the p-value is used for hypothesis testing, the null hypothesis is rejected if
p-value < = ?
In order to test the following hypotheses at an ? level of significance
H0: ? <= 100
Ha: ? > 100
the null hypothesis will be rejected if the test statistic Z is
> = Z?
Which of the following does not need to be known in order to compute the p-value?
the level of significance
In the hypothesis testing procedure, ? is
the level of significance
Your investment executive claims that the average yearly rate of return on the stocks she recommends is more than 10.0%. You plan on taking a sample to test her claim. The correct set of hypotheses is
H0: ? <= 10.0% Ha: ? > 10.0%
A weatherman stated that the average temperature during July in Chattanooga is less than 80 degrees. A sample of 32 Julys is taken. The correct set of hypotheses is
H0: ? >= 80 Ha: ? < 80
A student believes that the average grade on the final examination in statistics is at least 85. She plans on taking a sample to test her belief. The correct set of hypotheses is
H0: ? >= 85 Ha: ? < 85
The school's newspaper reported that the proportion of students majoring in business is more than 30%. You plan on taking a sample to test the newspaper's claim. The correct set of hypotheses is
H0: P <= 0.30 Ha: P > 0.30
In the past, 75% of the tourists who visited Chattanooga went to see Rock City. The management of Rock City recently undertook an extensive promotional campaign. They are interested in determining whether the promotional campaign actually increased the pr
H0: P <= 0.75 Ha: P > 0.75
The average life expectancy of tires produced by the Whitney Tire Company has been 40,000 miles. Management believes that due to a new production process, the life expectancy of their tires has increased. In order to test the validity of their belief, the
H0: ? <= 40,000 Ha: ? > 40,000
A soft drink filling machine, when in perfect adjustment, fills the bottles with 12 ounces of soft drink. Any over filling or under filling results in the shutdown and readjustment of the machine. To determine whether or not the machine is properly adjust
H0: ? = 12 Ha: ? ? 12
The academic planner of a university thinks that at least 35% of the entire student body attends summer school. The correct set of hypotheses to test his belief is
. H0: P >= 0.35 Ha: P < 0.35
The manager of an automobile dealership is considering a new bonus plan in order to increase sales. Currently, the mean sales rate per salesperson is five automobiles per month. The correct set of hypotheses for testing the effect of the bonus plan is
H0: ? <= 5 Ha: ? > 5
If a hypothesis is rejected at the 5% level of significance, it
may be rejected or not rejected at the 1% level
If a hypothesis is not rejected at the 5% level of significance, it
will also not be rejected at the 1% level
The probability of rejecting a false null hypothesis is equal to
1 - ?
If the level of significance of a hypothesis test is raised from .01 to .05, the probability of a Type II error
will decrease
If a hypothesis is rejected at 95% confidence, it
will always be rejected at 90% confidence
For a two-tailed test at 86.12% confidence, Z =
1.48
For a one-tailed test (lower tail) at 93.7% confidence, Z =
-1.53
Read the Z statistic from the normal distribution table and circle the correct answer. A one-tailed test (upper tail) at 87.7% confidence; Z =
1.16
For a two-tailed test, a sample of 20 at 80% confidence, t =
1.328
For a one-tailed test (upper tail), a sample size of 18 at 95% confidence, t=
1.740
For a one-tailed test (lower tail), a sample size of 10 at 90% confidence, t=
-1.383
A two-tailed test is performed at 95% confidence. The p-value is determined to be 0.09. The null hypothesis
should not be rejected
For a two-tailed test at 98.4% confidence, Z =
2.41
For a one-tailed test (upper tail) at 93.7% confidence, Z =
1.53
For a one-tailed test (lower tail) with 22 degrees of freedom at 95% confidence, the value of t =
-1.717
For a one-tailed hypothesis test (upper tail) the p-value is computed to be 0.034. If the test is being conducted at 95% confidence, the null hypothesis
is rejected
In a two-tailed hypothesis test the test statistic is determined to be Z = -2.5. The p-value for this test is
0.0124
You know that the level of significance ( ? ) of a test is 5%, you can tell that the probability of committing a Type II error ( ? ) is A) 2.5%. B) 95%. C) 97.5%. D) unknown
95%
You have created a 95% confidence interval for ? with the result 10? ? ?15. What decision will you make if you test H0: ? =16 versus H1: ? s?16 at ? s=0.05?
Reject H0 in favor of H 1
You have created a 95% confidence interval for ? with the result 10? ? ?15. What decision will you make if you test H00: ? =16 versus H11: ? s?16 at ? s=0.10?
Reject H0 in favor of H1
The owner of a local nightclub has recently surveyed a random sample of n=250 customers of the club. She would now like to determine whether or not the mean age of her customers is greater than 30. If so, she plans to alter the entertainment to appeal to
H00 : ? ? 30 and H1 : ? > 30
How many Kleenex should the Kimberly Clark Corporation package of
tissues contain? Researchers determined that 60 tissues is the average
number of tissues used during a cold. Suppose a random sample of 100
Kleenex users yielded the following data on the n
t = (52 - 60) / (22 / 10)
How many Kleenex should the Kimberly Clark Corporation package of
tissues contain? Researchers determined that 60 tissues is the average
number of tissues used during a cold. Suppose a random sample of 100
Kleenex users yielded the following data on the n
Reject H0: if t<- 1.6604
How many Kleenex should the Kimberly Clark Corporation package of
tissues contain? Researchers determined that 60 tissues is the average
number of tissues used during a cold. Suppose a random sample of 100
Kleenex users yielded the following data on the n
at 0.05, we reject H0
A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors results
-2.33
A survey claims that 9 out of 10 doctors recommend aspirin for their patients with headaches. To test this claim against the alternative that the actual proportion of doctors who recommend aspirin is less than 0.90, a random sample of 100 doctors was sele
There is sufficient evidence that the proportion of doctors who recommend aspirin is less than 0.90.
The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocassette recorders (VCRs). It conducts a telephone poll of 300 randomly selected households in the area and finds that 96 have VCRs.
2.80
A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocasset
0.0026
A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocasset
to reject H0 in favor of H1 .
A major videocassette rental chain is considering opening a new store in an area that currently does not have any such stores. The chain will open if there is evidence that more than 5,000 of the 20,000 households in the area are equipped with videocasset
to open a new store
An entrepreneur is considering the purchase of a coin-operated laundry. The current owner claims that over the past 5 years, the average daily revenue was $675 with a standard deviation of $75. A sample of 30 days reveals a daily average revenue of $625.
There is not enough evidence to conclude that the daily average revenue was not $675
A manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the average owed is $83.40 with a s
t-test of a population mean
A manager of the credit department for an oil company would like to determine whether the average monthly balance of credit card holders is equal to $75. An auditor selects a random sample of 100 accounts and finds that the average owed is $83.40 with a s
There is evidence that the average balance is not $75.
The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a passenger-side inflatable air bag if it had been available for an additional cost of $300. The manager be
Z-test of a population proportion
The marketing manager for an automobile manufacturer is interested in determining the proportion of new compact-car owners who would have purchased a passenger-side inflatable air bag if it had been available for an additional cost of $300. The manager be
There is not sufficient evidence that the proportion is not 0.30
Microsoft Excel was used on a set of data involving the number of parasites found on 46 Monarch butterflies captured in Pismo Beach State Park. A biologist wants to know if the mean number of parasites per butterfly is over 20. She will make her decision
the mean number of parasites on Monarch butterflies in Pismo Beach State Park
Referring to Table 9-1, state the alternative hypothesis for this study.
H1: > 20.000
Referring to Table 9-1, what critical value should the biologist use to determine the rejection region?
1.3006
A spouse suspects that the average amount of money spent on Christmas gifts for immediate family members is above $1,200. The correct set of hypotheses is:
H0: ? = 1200 vs. H1: ? > 1200
In testing the hypothesis H0: ? = 100 vs. H1: ? > 100, the p-value is found to be 0.074, and the sample mean is 105. Which of the following statements is true?
The probability of observing a sample mean at least as large as 105 from a population whose mean is 100 is 0.074
A random sample of 8 observations was drawn from a normal population. The sample mean and population standard deviation are 40 and 10 respectively. Estimate the population mean with 95% confidence (to 2 decimals)
(33.07, 46.93)
A random sample of 8 observations was drawn from a normal population. The sample mean and sample standard deviation are 40 and 10 respectively. Estimate the population mean with 95% confidence (to 2 decimals).
(31.64, 48.36)
The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with ? = 110 grams and ? = 25 grams. What is the probability that a randomly selected vitamin will contain between 100 and 110 grams of pyridoxine?
0.1554
The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with = 110 grams and = 25 grams. What is the probability that a randomly selected vitamin will contain between 82 and 100 grams of pyridoxine?
0.2132
The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with = 110 grams and = 25 grams. What is the probability that a randomly selected vitamin will contain at least 100 grams of pyridoxine?
0.6554
The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with = 110 grams and = 25 grams. What is the probability that a randomly selected vitamin will contain between 100 and 120 grams of pyridoxine?
0.3108
The amount of pyridoxine (in grams) in a multiple vitamin is normally distributed with = 110 grams and = 25 grams. What is the probability that a randomly selected vitamin will contain less than 100 grams of pyridoxine?
0.3446
The managers of a company are worried about the morale of their employees. In order to determine if a problem in this area exists, they decide to evaluate the attitudes of their employees with a standardized test. They select the Fortunato test of job sat
63
The managers of a company are worried about the morale of their employees. In order to determine if a problem in this area exists, they decide to evaluate the attitudes of their employees with a standardized test. They select the Fortunato test of job sat
82.12 to 93.88
A quality control engineer is interested in the mean length of sheet insulation being cut automatically by machine. The desired length of the insulation is 12 feet. It is known that the standard deviation in the cutting length is 0.15 feet. A sample of 70
2.58
A quality control engineer is interested in the mean length of sheet insulation being cut automatically by machine. The desired length of the insulation is 12 feet. It is known that the standard deviation in the cutting length is 0.15 feet. A sample of 70
12.09 to 12.19
Which of the following would be an appropriate null hypothesis?
the mean of a population is equal to 55
Which of the following would be an appropriate null hypothesis?
The mean of the population is equal to 55
Which of the following would be an appropriate null hypothesis?
The population proportion is no less than 0.65.
Which of the following would be an appropriate alternative hypothesis?
The mean of a population is greater than 55.
Which of the following would be an appropriate alternative hypothesis?
The population proportion is less than 0.65.
It is desired to estimate the average total compensation of CEOs in the Service industry. Data were randomly collected from 18 CEOs and the 95% confidence interval was calculated to be ($2,181,260, $5,836,180). Based on the interval above, do you believe
I cannot conclude that the average exceeds $3,000,000 at the 97% confidence level
data was randomly collected from 18 CEOs and the 97% confidence interval was calculated to be ($2,181,260, $5,836,180). Which of the following interpretations is correct?
We are 97% confident that the average total compensation of all CEOs in the service falls in the interval $2,181,260 to $5,836,180
A confidence interval was use to estimate the proportion of statistics students that are females. A random sample of 72 students generated the following 90% confidence interval: (0.438, 0.642). Based on the interval score, is the population proportion of
Maybe. 0.60 is a believable value of the population proportion based on the information above
A confidence interval was use to estimate the proportion of statistics students that are females. A random sample of 72 students generated the following 90% confidence interval: (0.438, 0.642). Using the information above, what size sample would be necess
150
When determining the sample size necessary for estimating the true population mean, which factor is NOT considered when sampling with replacement?
the population size
An appliance manufacturer claims to have developed a compact microwave oven that consumes an average of no more than 250 W. From previous studies, it is believed that power consumption for microwave ovens is normally distributed with a standard deviation
the power consumption in a such microwave ovens
Referring to table 9-3, the parameter of interest is
the mean power consumption of all such microwave ovens
referring to table 9-3, the appropriate hypothesis to determine if the manufacturer's claim appears reasonable are:
H0: 250 versus H1: 250
Referring to table 9-3, for a test with a significance level of 0.05, the critical value would be
z= 1.645
referring to table 9-3 the value of the test statistic is
2.18
referring to table 9-3, the p-value of the test is
0.0148
The width of a confidence interval estimate for a proportion will be
narrower for 90% confidence than for 95% confidence.
When determining the sample size for a proportion for a given level of confidence and sampling error, the closer to 0.50 that p is estimated to be, the __________ the sample size required.
larger
A 99% confidence interval estimate can be interpreted to mean that
both of the above
If you were constructing a 99% confidence interval of the population mean based on a sample of n = 25, where the standard deviation of the sample s = 0.05, the critical value of t will be
2.7970
Confidence Interval Estimation
It is used to construct confidence intervals for the population mean when the population standard deviation is known.
In a hypothesis test involving a population mean, which of the following would be an acceptable formulation?
H0 : = $1,700 Ha : > $1,700
if the p value is less than a in a two-tailed test,
the null hypothesis should be rejected.
Compute the p-value assuming that the hypothesis test is a one-tailed test: z = 1.34
0.0901
compute the p-value assuming that the hypothesis test is a one-tailed test: z = -1.55.
0.0606
A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random
1.645
A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random
16.041 ounces
The cost of a college education has increased at a much faster rate than costs in general over the past twenty years. In order to compensate for this, many students work part- or full-time in addition to attending classes. At one university, it is believe
is approximately equal to 25.26 hours
If a manager believes that the required sample size is too large for a situation in which she desires to estimate the mean income of blue collar workers in a state, which of the following would lead to a reduction in sample size?
All options are correct
A 90% confidence interval is found to be:
$6.72 +- 2.38
$4.34 ----- $9.10
Which is the best statement?
Based on the sample data, we are 90% confident the population mean will be between $4.34 and $9.10.
The reason for using the t-distribution in a hypothesis test about the population mean is:
The pop standard deviation is unknown
A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.10 level of significance and a random
Ho: � = 16
Ha: � ? 16
The R.D. Wilson Company makes a soft drink dispensing machine that allows customers to get soft drinks from the machine in a cup with ice. When the machine is running properly, the average number of fluid ounces in the cup should be 14. Periodically the m
Mu=14
An analyst plans to test whether the standard deviation for the time it takes bank tellers to provide service to customers exceeds the standard of 1.5 minutes. The correct null and alternative hypothesis for this test are:
Ho: ?2 ? 2.25
Ha: ?2 > 2.25
If a hypothesis test for a single population variance is to be conducted, which of the following statements is true
All of the following statements are true
If the variance of the contents of cans of orange juice is significantly more than 0.003, the manager has to order to stop the filling machine. A sample of 26 cans of orange juice showed a standard deviation of 0.06 ounces. Based on the sample and at the
stopped
The R.D. Wilson Company makes a soft drink dispensing machine that allows customers to get soft drinks from the machine in a cup with ice. When the machine is running properly, the average number of fluid ounces in the cup should be 14. Periodically the m
The null hypothesis cannot be rejected since the test statistic is approximately t = 0.20, which is not in the rejection region.
When testing a two-tailed hypothesis using a significance level of 0.05, a sample size of n = 16, and with the population standard deviation unknown, which of the following is true?
All of the above are true
A house cleaning service claims that it can clean a four bedroom house in less than 2 hours. A sample of n = 16 houses is taken and the sample mean is found to be 1.97 hours and the sample standard deviation is found to be 0.1 hours. Using a 0.05 level of
To not reject the null because the test statistic (-1.2) is > the critical value (-1.7531).
Woof Chow Dog Food Company believes that it has a market share of 25 percent.
It surveys n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food. The appropriate null and alternate hypotheses are:
H0 : p = .25 Ha : p ?.25
Woof Chow Dog Food Company believes that it has a market share of 25%. They survey n = 100 dog owners and ask whether or not Woof Chow is their regular brand of dog food, and 23 people say yes. Based upon this information, what is the value of the test st
-0.462
A company that makes shampoo wants to test whether the average amount of shampoo per bottle is 16 ounces. The standard deviation is known to be 0.20 ounces. Assuming that the hypothesis test is to be performed using 0.05 level of significance and a random
16.049 ounces
The managers of a local golf course have recently conducted a study of the types of golf balls used by golfers based on handicap. A joint frequency table for the 100 golfers covered in the survey is show below:
If a player comes to the course using a Nike
0.455.
Suppose we want to test Ho:(mew) = 30 Ha: <0 Which of the following possible sample results based on a sample of size 36 gives the strongest evidence to reject H0 in favor of Ha?
X= 27, s = 4
The Hilbert Drug Store owner plans to survey a random sample of his customers with the objective of estimating the mean dollars spent on pharmaceutical products during the past three months. He has assumed that the population standard deviation is known t
231
The chamber of commerce in a beach resort town wants to estimate the proportion of visitors who are repeat visitors. From previous experience they believe the portion is in the vicinity of 0.5 and they want to estimate the proportion to within � 0.03 perc
n=1068
A sample of 250 people resulted in a confidence interval estimate for the proportion of people who believe that the federal government's proposed tax increase is justified is between 0.14 and 0.20. Based on this information, what was the confidence level
Approximately 79 percent
A large Midwestern university is interested in estimating the mean time that students spend at the student recreation center per week. A previous study indicated that the standard deviation in time is about 40 minutes per week. If the officials wish to es
44
What sample size is needed to estimate a population mean within �50 of the true mean value using a confidence level of 95%, if the true population variance is known to be 122,500?
189
The file Danish Coffee contains a random sample of 144 Danish coffee drinkers and measures the annual coffee consumption in kilograms for each sampled coffee drinker. A marketing research firm wants to use this information to develop an advertising campai
6.5368