54. Which of the following does NOT hold true for the t distribution?
A) Confidence intervals will be wider than for large samples.
B) The region of acceptance will be larger than for large samples.
C) A larger computed t value will be needed to reject the null hypothesis than for large samples using z.
D) There is only one
55. What value does the null hypothesis make a claim about?
A) Population parameter
B) Sample statistic
C) Sample mean
D) Type II error
Answer: A
56. A p-value can be computed for
A) a hypothesis test about a population mean
B) a hypothesis test about a population proportion.
C) a hypothesis test about a population mean based on a sample size of 10.
D) A, B, and C
Answer: A
57. Test at the 0.01 level the statement that 55% of those families who plan to purchase a vacation residence in Florida want a condominium. The null hypothesis is = 0.55 and the alternate is 0.55. A random sample of 400 families who planned to buy a vac
A) Do not reject it
B) Reject it
C) Cannot accept nor reject it based on the information given
D) None of the above
Answer: A
58. What is the level of significance?
A) Probability of a Type II error
B) Probability of a Type I error
C) z-value of 1.96
D) Beta error
Answer: B
59. The mean length of a small counter balance bar is 43 millimeters. There is concern that the adjustments of the machine producing the bars have changed. Test the claim at the 0.02 level that there has been no change in the mean length. The alternate hy
A) Yes, because the computed t lies in the area beyond the critical.
B) No, because the information given is not complete.
C) No, because the computed t lies in the area to the right of -2.718.
D) None of the above
Answer: A
60. From past records it is known that the average life of a battery used in a digital clock is 305 days. The battery life is normally distributed. The battery was recently modified to last longer. A sample of 20 of the modified batteries was tested. It w
A) Do not reject the null hypothesis if computed t is 1.96 or greater
B) Reject the null hypothesis if computed t is less than 1.96
C) Do not reject the null hypothesis if computed t is 1.729 or greater
D) Reject the null hypothesis if computed t is 2.086
61. A manufacturer wants to increase the shelf life of a line of cake mixes. Past records indicate that the average shelf life of the mix is 216 days. After a revised mix has been developed, a sample of nine boxes of cake mix gave these shelf lives (in da
A) Yes, because computed t is greater than the critical value.
B) Yes, because computed t is less than the critical value.
C) No, because computed t lies in the region of acceptance.
D) No, because 217.24 is quite close to 216.
Answer: A
62. A manufacturer wants to increase the absorption capacity of a sponge. Based on past data, the average sponge could absorb 3.5 ounces. After the redesign, the absorption amounts of a sample of sponges were (in ounces): 4.1, 3.7, 3.3, 3.5, 3.8, 3.9, 3.6
A) Do not reject null hypothesis if computed t is less than 2.580
B) Do not reject null hypothesis if computed t is less than 2.821
C) Reject null hypothesis if computed z is 1.96 or larger
D) Reject null hypothesis if computed t is less than 2.764
Answer
63. A machine is set to fill the small size packages of M&M candies with 56 candies per bag. A sample revealed: 3 bags of 56, 2 bags of 57, 1 bag of 55, and 2 bags of 58. How many degrees of freedom are there?
A) 9
B) 1
C) 8
D) 7
Answer: D
64. A random sample of size 15 is selected from a normal population. The population standard deviation is unknown. Assume that a two-tailed test at the 0.10 significance level is to be used. For what value of t will the null hypothesis not be rejected?
A) To the left of -1.282 or to the right of 1.282
B) To the left of -1.345 or to the right of 1.345
C) To the left of -1.761 or to the right of 1.761
D) To the left of -1.645 or to the right of 1.645
Answer: C
65. What is the critical value for a one-tailed hypothesis test in which a null hypothesis is tested at the 5% level of significance based on a sample
size of 25?
A) 1.708
B) 1.711
C) 2.060
D) 2.064
Answer: B
66. To conduct a test of hypothesis with a small sample, we need to be able to make the following assumption that:
A) a larger computed value of t will be needed to reject the null hypothesis
B) the region of acceptance will be wider than for large samples
C) the confidence interval will be wider than for large samples
D) the population is normally distributed.
Answer
67. What do we call the statement that determines if the null hypothesis is rejected?
A) Decision rule
B) Test statistic
C) Alternate hypothesis
D) Critical value
Answer: A
68. What is a Type II error?
A) Accepting a false null hypothesis
B) Rejecting a false null hypothesis
C) Accepting a false alternate hypothesis
D) Rejecting a false alternate hypothesis
Answer: A
69. If the alternate hypothesis states that does not equal 4,000, what is the rejection region for the hypothesis test?
A) Both tails
B) Lower or left tail
C) Upper or right tail
D) Center
Answer: A
70. What are the two rejection areas in using a two-tailed test and the 0.01 level of significance when n is large and the population standard deviation is known?
A) Above 1.96 and below -1.96
B) Above 1.65 and below -1.65
C) Above 2.58 and below -2.58
D) Above 1.00 and below -1.00
Answer: C
71. If the 1% level of significance is used and the computed value of z is +6.00, what is our decision?
A) Do not reject H0
B) Reject H0
C) Reject H1
D) None of the above
Answer: B
72. What is another name for the alternate hypothesis?
A) Null hypothesis
B) Hypothesis of no difference
C) Rejected hypothesis
D) Research hypothesis
Answer: D
73. For a two-tailed test at the 0.05 significance level, what is the rejection region when n if large and the population standard deviation is known?
A) Between 1.96
B) Between 1.65
C) Greater than +1.96 and less than - 1.96
D) Greater than +1.65 and less than -1.65
Answer: C
74. The sample size and the population proportion are respectively represented by what symbols?
A) p and n
B)
C) z and t
D) n and
Answer: D
75. What is the probability of making a Type II error if the null hypothesis is actually true?
A)
B) 1
C) 0
D) 0.05
Answer: C
76. Which of the following is a test statistic used to test a hypothesis about a population parameter?
A)
B)
C)
D) z
Answer: D
77. If = 0.05 for a two-tailed test, how large is the acceptance area?
A) 0.050
B) 0.025
C) 0.950
D) 0.975
Answer: C
78. If the alternative hypothesis states that > 6,700, what is the rejection region for the hypothesis test?
A) Both tails
B) Lower tail
C) Upper tail
D) Center
Answer: C
79. What are the critical z-values for a two-tailed hypothesis test if = 0.01?
A) � 1.96
B) � 2.33
C) � 2.58
D) � 1.65
Answer: C
80. If the critical z-value for a test statistic equals 2.45, what value of the test statistic would guarantee no chance of making a Type I error?
A) 3.74
B) 10,000
C) 2.46
D) 4.56
Answer: B
81. For a one-tailed hypothesis test, the critical z-value of the test statistic is -2.33. Which of the following is true about the hypothesis test?
A) = 0.05 for a lower-tailed test
B) = 0.01 for a lower-tailed test
C) = 0.05 for an upper-tailed test
D) = 0.01 for an upper-tailed test
Answer: B
82. If we reject the null hypothesis what can we conclude subject to the risk?
A) Null hypothesis is false
B) Alternative hypothesis is false
C) Null hypothesis is true
D) Both the null hypothesis and the alternative hypothesis are true
E) Both the null hypothesis and the alternative hypothesis are false
Answer: A
83. Which of the following is NOT one of the five steps in the hypothesis testing procedure?
A) Formulate a decision rule
B) State the null and alternate hypotheses
C) Select a level for
D) Identify the test statistic
E) All of the above are part of the five steps
Answer: C
84. A manufacturer of stereo equipment introduces new models in the fall. Retail dealers are surveyed immediately after the Christmas selling season regarding their stock on hand of each piece of equipment. It has been discovered that unless 40% of the ne
A) Cut back production
B) Do not cut back production
C) Cannot determine based on information given
D) None of the above
Answer: B
85. If 20 out of 50 students sampled live in a college dormitory, what is the estimated proportion of students at the University living in a dormitory?
A) 0.20
B) 0.40
C) 0.50
D) 0.60
Answer: B
86. What does z equal for an = 0.01 and a left tail test?
A) +2.33
B) -2.33
C) +2.58
D) -2.58
Answer: B
87. What do tests of proportions require of both n and n(1 - )?
A) Exceed 30
B) Exceed 5
C) Exceed 100
D) Be equal
Answer: B
88. If = 0.05, what is the probability of making a Type I error?
A) 0
B) 1/20
C) 19/20
D) 20/20
Answer: B
89. The claim that "40% of those persons who retired from an industrial job before the age of 60 would return to work if a suitable job was available," is to be investigated at the 0.02 level of risk. If 74 out of the 200 workers sampled said they would r
A) Do no reject the null hypothesis because -0.866 lies in the region between 0 and -2.33
B) Do not reject the null hypothesis because -0.866 lies in the region between 0 and -2.58
C) Reject the null hypothesis because 37% is less than 40%
D) Do not rejec
90. In hypothesis testing, what is the level of significance?
A) Risk of rejecting the null hypothesis when it is true
B) Symbolized by the Greek letter " "
C) Value between 0 and 1
D) Selected before a decision rule can be formulated
E) All of the above are true
Answer: E
91. Which symbol represents a population proportion?
A) pc
B) z
C)
D)
Answer: D
92. What is the sample proportion defined as?
A) n
B) x/n
C) n!
D)
Answer: B
Use the following to answer questions 114-118:
The average cost of tuition, room and board at small private liberal arts colleges is reported to be $8,500 per term, but a financial administrator believes that the average cost is higher. A study conducted
A) Null: $9,000; alternative: > $9,000
B) Null: $9,000; alternative: < $9,000
C) Null: $8,500; alternative: > $8,500
D) Null: $8,500; alternative: < $8,500
Answer: C
115. What is the critical z-value for this test?
A) + 1.96
B) - 1.96
C) + 1.65
D) - 1.65
Answer: C
116. What is the test statistic for this test?
A) �3.82
B) 0.204
C) -3.82
D) +3.82
Answer: D
117. What is the p-value for this test?
A) 0.0000
B) 0.0124
C) 0.0500
D) 0.4938
Answer: A
118. Based on the computed test statistic or p-value, what is our decision about the average cost?
A) Equal to $8,500
B) Greater than $8,500
C) Less than $8,500
D) Not equal to $8,500
Answer: B
Use the following to answer questions 129-136:
Based on the Nielsen ratings, the local CBS affiliate claims its 11:00 PM newscast reaches 41% of the viewing audience in the area. In a survey of 100 viewers, 36% indicated that they watch the late evening n
A) = 0.36
B) = 0.41
C) 0.36
D) = 0.41
Answer: B
130. What is the alternate hypothesis?
A) = 0.36
B) = 0.41
C) 0.41
D) 0.41
Answer: C
131. What is the sample proportion?
A) 0.41
B) 0.36%
C) 0.41%
D) 0.36
Answer: D
132. What is the critical value if = 0.01?
A) 2.58
B) 2.33
C) 2.58
D) -2.33
Answer: C
133. What is the z-statistic?
A) 1.02
B) 1.22
C) -1.02
D) -1.22
Answer: C
134. What is the p-value?
A) 0.3461
B) 0.1539
C) 0.3078
D) 0.0100
Answer: B
135. What is the critical value if the level of significance is 0.10?
A) -1.282
B) 1.65
C) -2.58
D) 2.58
Answer: B
136. What is your decision if = 0.01?
A) Fail to reject the null hypothesis and conclude the newscast reaches about 41% of the audience.
B) Reject the null hypothesis and conclude the newscast does not reach 41% of the audience.
C) Fail to reject the alternate and conclude the newscast does n
Use the following to answer questions 137-143:
It is claimed that in a bushel of peaches less than ten percent are defective. A sample of 400 peaches is examined and 50 are found to be defective.
137. What is the null hypothesis?
A) 0.10
B) 0.10
C) 0.10
D) < 0.10
E) = 0.10
Answer: B
138. What is the alternate hypothesis for a one-sided test?
A) 0.10
B) > 0.10
C) 0.10
D) = 0.10
E) < 0.10
Answer: E
139. What is the critical value for = 0.025?
A) 1.96
B) 1.65
C) - 1.96
D) -1.65
Answer: C
140. What is the sample proportion?
A) 0.10
B) 0.125
C) 40
D) 0.40
Answer: B
141. What is the z-statistic?
A) 0.025
B) 0.278
C) -1.65
D) 1.67
Answer: D
142. What is the p-value?
A) 0.025 0
B) 0.4525
C) 0.0475
D) 0.0500
Answer: C
143. If = 0.025, what will be the decision?
A) Fail to reject the null and conclude the defects are not greater than 10%
B) Reject the null and conclude the defects are not greater than 10%
C) Reject the null and conclude the defects are greater than 10%
D) Fail to reject the null and conclude the
Use the following to answer questions 144-146:
The mean gross annual incomes of certified welders are normally distributed with the mean of $20,000 and a standard deviation of $2,000. The ship building association wishes to find out whether their welders
A) Do not reject the null hypothesis if computed z lies between -1.65 and +1.65; otherwise, reject it
B) Do not reject the null hypothesis if computed z is greater than 1.65; otherwise, reject it
C) Do not reject the null hypothesis if computed z lies bet
145. Which of the following is the alternate hypothesis?
A) $20,000
B) $20,000
C) $20,000
D) = $20,000
E) = $20,000
Answer: B
146. If the level of significance is 0.10, what is the critical value?
A) 1.65
B) 2.58
C) 1.28
D) 1.28
E) 1.65
Answer: E
Use the following to answer questions 147-155:
The mean weight of newborn infants at a community hospital is 6.6 pounds. A sample of seven infants is randomly selected and their weights at birth are recorded as 9.0, 7.3, 6.0, 8.8, 6.8, 8.4, and 6.6 pounds
A) = 6.6
B) 6.6
C) 6.6
D) > 7.6
E) 7.6
Answer: A
148. What is the alternate hypothesis?
A) = 6.6
B) 6.6
C) 6.6
D) > 7.6
E) 7.6
Answer: B
149. What is the degrees of freedom?
A) 7
B) 8
C) 6
D) 6.6
E) 7.6
Answer: C
150. If = 0.05, what is the critical t value?
A) - 2.365
B) 1.96
C) 2.365
D) 2.447
E) - 2.447
Answer: D
151. What is the sample mean?
A) 6.6
B) 7.6
C) 1.177
D) 2.447
Answer: B
152. What is the sample variance?
A) 1.177
B) 6.6
C) 1.385
D) 7.6
Answer: C
153. What is the sample standard deviation?
A) 1.177
B) 6.6
C) 1.385
D) 7.6
Answer: A
154. What is the decision for a statistical significant change in average weights at birth at the 5% level of significance?
A) Fail to reject the null hypothesis and conclude the mean is 6.6 lb.
B) Reject the null hypothesis and conclude the mean is higher than 6.6 lb.
C) Reject the null hypothesis and conclude the mean is lower than 6.6 lb.
D) Cannot calculate because populat
155. What is the decision for a significant increase in the average birthrate at a 5% level of significance?
A) Fail to reject the null hypothesis and conclude the mean is 6.6 lb.
B) Reject the null hypothesis and conclude the mean is lower than 6.6 lb.
C) Reject the null hypothesis and conclude the mean is greater than 6.6 lb.
D) Cannot calculate because popula