The center of a normal curve is
is the mean of the distribution
The probability that a continuous random variable takes any specific value
is equal to zero
A normal distribution with a mean of 0 and a standard deviation of 1 is called
a standard normal distribution
The z score for the standard normal distribution
can be either negative or positive
In a standard normal distribution, the probability that Z is greater than 0.5 is
0.5
A negative value of Z indicates that
the number of standard deviations of an observation is to the left of the mean
The uniform, normal, and exponential distributions are
all continuous probability distributions
A value of 0.5 that is added and/or subtracted from a value of x when the continuous normal distribution is used to approximate the discrete binomial distribution is called
continuity correction factor
For a continuous random variable x, the probability density function f(x) represents
the height of the function at x
The uniform probability distribution is used with
a continuous random variable
For any continuous random variable, the probability that the random variable takes on exactly a specific value is
almost zero
For the standard normal probability distribution, the area to the left of the mean is
0.5
Which of the following is not a characteristic of the normal probability distribution?
The standard deviation must be 1
In a standard normal distribution, the range of values of z is from
minus infinity to infinity
For a uniform probability density function,
the height of the function is the same for each value of x
The probability density function for a uniform distribution ranging between 2 and 6 is
0.25
A uniform probability distribution is a continuous probability distribution where the probability that the random variable assumes a value in any interval of equal length is
the same for each interval
The function that defines the probability distribution of a continuous random variable is a
probability density function
When a continuous probability distribution is used to approximate a discrete probability distribution
a value of 0.5 is added and/or subtracted from the value of x
A continuous probability distribution that is useful in describing the time, or space, between occurrences of an event is a(n)
Poisson probability distribution
The exponential probability distribution is used with
a continuous random variable
Consider a binomial probability experiment with n = 3 and p = 0.1. Then, the probability of x = 0 is
0.729
Larger values of the standard deviation result in a normal curve that is
wider and flatter
Which of the following is not a characteristic of the normal probability distribution?
99.72% of the time the random variable assumes a value within plus or minus 1 standard deviation of its mean
For a normal distribution, a negative value of z indicates
the z is to the left of the mean
The mean of a standard normal probability distribution
is always equal to zero
The standard deviation of a standard normal distribution
is always equal to one
A normal probability distribution
is a continuous probability distribution
A continuous random variable may assume
all values in an interval or collection of intervals
A continuous random variable is uniformly distributed between a and b. The probability density function between a and b is
1/(b - a)
If the mean of a normal distribution is negative,
None of these alternatives is correct.
For a standard normal distribution, the probability of z 0 is
0.5
The highest point of a normal curve occurs at
the mean
The random variable x is known to be uniformly distributed between 70 and 90. The probability of x having a value between 80 to 95 is
0.5
Z is a standard normal random variable. The P(-1.96 Z -1.4) equals
0.0558
A standard normal distribution is a normal distribution
with a mean of 0 and a standard deviation of 1
Z is a standard normal random variable. The P (1.20 Z 1.85) equals
0.0829
Z is a standard normal random variable. The P (-1.20 Z 1.50) equals
0.8181
Given that Z is a standard normal random variable, what is the probability that -2.51 Z -1.53?
0.0570
Given that Z is a standard normal random variable, what is the probability that Z -2.12?
0.9830
Given that Z is a standard normal random variable, what is the probability that -2.08 Z 1.46?
0.9091
Z is a standard normal random variable. The P (1.41 < Z < 2.85) equals
0.0771
X is a normally distributed random variable with a mean of 8 and a standard deviation of 4. The probability that X is between 1.48 and 15.56 is
0.9190
X is a normally distributed random variable with a mean of 5 and a variance of 4. The probability that X is greater than 10.52 is
0.0029
X is a normally distributed random variable with a mean of 12 and a standard deviation of 3. The probability that X equals 19.62 is
0.000
X is a normally distributed random variable with a mean of 22 and a standard deviation of 5. The probability that X is less than 9.7 is
0.0069
Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.5?
0.0000
Given that Z is a standard normal random variable, what is the value of Z if the are to the left of Z is 0.0559?
1.59
An exponential probability distribution
is a continuous distribution
Z is a standard normal random variable. What is the value of Z if the area to the right of Z is 0.1112?
1.22
Z is a standard normal random variable. What is the value of Z if the area between -Z and Z is 0.754?
1.16
Z is a standard normal random variable. What is the value of Z if the area to the right of Z is 0.9803?
-2.06
For a standard normal distribution, the probability of obtaining a z value between -2.4 to -2.0 is
0.0146
For a standard normal distribution, the probability of obtaining a z value of less than 1.6 is
0.9452
For a standard normal distribution, the probability of obtaining a z value between -1.9 to 1.7 is
0.9267
The ages of students at a university are normally distributed with a mean of 21. What percentage of the student body is at least 21 years old?
50%
Z is a standard normal random variable. The P(1.05 < Z < 2.13) equals
0.1303
Z is a standard normal random variable. The P(Z > 2.11) equals
0.0174
Z is a standard normal random variable. The P(-1.5 < Z < 1.09) equals
0.7953
Given that Z is a standard normal random variable. What is the value of Z if the area to the left of Z is 0.9382?
1.54
Given that Z is a standard normal random variable. What is the value of Z if the area to the right of Z is 0.1401?
1.08
Given that Z is a standard normal random variable, what is the value of Z if the area to the right of Z is 0.9834?
-2.13
Given that Z is a standard normal random variable. What is the value of Z if the area between -Z and Z is 0.754?
1.16
Given that Z is a standard normal random variable, what is the value of Z if the area to the left of Z is 0.119?
-1.18
Given that Z is a standard normal random variable, what is the value of Z if the area between -Z and Z is 0.901?
1.65
Use the normal approximation to the binomial distribution to answer this question. Fifteen percent of all students at a large university are absent on Mondays. If a random sample of 12 names is called on a Monday, what is the probability that four student
0.0683
Exhibit 6-1
The assembly time for a product is uniformly distributed between 6 to 10 minutes.
67. Refer to Exhibit 6-1. The probability density function has what value in the interval between 6 and 10?
0.25
Refer to Exhibit 6-1. The probability of assembling the product between 7 to 9 minutes is
0.50
Refer to Exhibit 6-1. The probability of assembling the product in less than 6 minutes
zero
Refer to Exhibit 6-1. The probability of assembling the product in 7 minutes or more
0.75
Refer to Exhibit 6-1. The expected assembly time (in minutes) is
8
Refer to Exhibit 6-1. The standard deviation of assembly time (in minutes) is approximately
1.1547
Exhibit 6-2
The weight of football players is normally distributed with a mean of 200 pounds and a standard deviation of 25 pounds.
Refer to Exhibit 6-2. The probability of a player weighing more than 241.25 pounds is
0.0495
Refer to Exhibit 6-2. The probability of a player weighing less than 250 pounds is
0.9772
Refer to Exhibit 6-2. What percent of players weigh between 180 and 220 pounds?
57.62%
Refer to Exhibit 6-2. What is the minimum weight of the middle 95% of the players?
151
Exhibit 6-3
Consider the continuous random variable X, which has a uniform distribution over the interval from 20 to 28.
77. Refer to Exhibit 6-3. The probability density function has what value in the interval between 20 and 28?
0.125
Refer to Exhibit 6-3. The probability that X will take on a value between 21 and 25 is
0.500
Refer to Exhibit 6-3. The probability that X will take on a value of at least 26 is
0.250
Refer to Exhibit 6-3. The mean of X is
24
Refer to Exhibit 6-3. The variance of X is approximately
5.333
Exhibit 6-4
f(x) =(1/10) e-x/10 x 0
Refer to Exhibit 6-4. The mean of x is
10
Refer to Exhibit 6-4. The probability that x is between 3 and 6 is
0.1920
Refer to Exhibit 6-4. The probability that x is less than 5 is
0.3935
Exhibit 6-5
The travel time for a college student traveling between her home and her college is uniformly distributed between 40 and 90 minutes.
85. Refer to Exhibit 6-5. The probability that she will finish her trip in 80 minutes or less
0.8
Refer to Exhibit 6-5. The probability that her trip will take longer than 60 minutes is
0.600
Refer to Exhibit 6-5. The probability that her trip will take exactly 50 minutes is
zero
Exhibit 6-6
The starting salaries of individuals with an MBA degree are normally distributed with a mean of $40,000 and a standard deviation of $5,000.
88. Refer to Exhibit 6-6. What is the probability that a randomly selected individual with an MBA degre
0.9772
Refer to Exhibit 6-6. What is the probability that a randomly selected individual with an MBA degree will get a starting salary of at least $47,500?
0.0668
Refer to Exhibit 6-6. What percentage of MBA's will have starting salaries of $34,000 to $46,000?
76.98%
Exhibit 6-7
The weight of items produced by a machine is normally distributed with a mean of 8 ounces and a standard deviation of 2 ounces.
91. Refer to Exhibit 6-7. What is the probability that a randomly selected item will weigh more than 10 ounces?
0.1587
Refer to Exhibit 6-7. What is the probability that a randomly selected item will weigh between 11 and 12 ounces?
0.0440
Refer to Exhibit 6-7. What percentage of items will weigh at least 11.7 ounces?
3.22%
Refer to Exhibit 6-7. What percentage of items will weigh between 6.4 and 8.9 ounces?
0.4617
Refer to Exhibit 6-7. What is the probability that a randomly selected item weighs exactly 8 ounces?
0.0000
Exhibit 6-8
The life expectancy of a particular brand of tire is normally distributed with a mean of 40,000 and a standard deviation of 5,000 miles.
96. Refer to Exhibit 6-8. What is the probability that a randomly selected tire will have a life of at lea
0.9772
Refer to Exhibit 6-8. What is the probability that a randomly selected tire will have a life of at least 47,500 miles?
0.0668
Refer to Exhibit 6-8. What percentage of tires will have a life of 34,000 to 46,000 miles?
76.98%
Refer to Exhibit 6-8. What is the probability that a randomly selected tire will have a life of exactly 47,500 miles?
0.0000
Exhibit 6-9
The average price of personal computers manufactured by MNM Company is $1,200 with a standard deviation of $220. Furthermore, it is known that the computer prices manufactured by MNM are normally distributed.
100. Refer to Exhibit 6-9. What is
0.0668
Refer to Exhibit 6-9. Computers with prices of more than $1,750 receive a discount. What percentage of the computers will receive the discount?
0.62%
Refer to Exhibit 6-9. What is the minimum value of the middle 95% of computer prices?
$768.80
Refer to Exhibit 6-9. If 513 of the MNM computers were priced at or below $647.80, how many computers were produced by MNM?
85,500
Exhibit 6-10
A professor at a local university noted that the grades of her students were normally distributed with a mean of 73 and a standard deviation of 11.
104. Refer to Exhibit 6-10. The professor has informed us that 7.93 percent of her students re
88.51
Refer to Exhibit 6-10. Students who made 57.93 or lower on the exam failed the course. What percent of students failed the course?
8.53%
Refer to Exhibit 6-10. If 69.5 percent of the students received grades of C or better, what is the minimum score of those who received C's?
67.39
The driving time for an individual from his home to his work is uniformly distributed between 300 to 480 seconds.
a.
Determine the probability density function.
b.
Compute the probability that the driving time will be less than or equal to 435 seconds.
c.
ANS:
a.
b.
0.75
c.
390
d.
2700
e.
51.96
The Body Paint, an automobile body paint shop, has determined that the painting time of automobiles is uniformly distributed and that the required time ranges between 45 minutes to 1 1/2 hours.
a.
Give a mathematical expression for the probability density
a.
b.
0.333
c
0.889
d.
67.5, 12.99
For a standard normal distribution, determine the probabilities of obtaining the following z values. It is helpful to draw a normal distribution for each case and show the corresponding area.
a.
Greater than zero
b.
Between -2.4 and -2.0
c.
Less than 1.6
a.
0.5
b.
0.146
c.
0.9452
d.
0.9267
e.
0.0267
A professor at a local community college noted that the grades of his students were normally distributed with a mean of 74 and a standard deviation of 10. The professor has informed us that 6.3 percent of his students received A's while only 2.5 percent o
a.
89.3
b.
54.4
c.
200
The time it takes to hand carve a guitar neck is uniformly distributed between 110 and 190 minutes.
a.
What is the probability that a guitar neck can be carved between 95 and 165 minutes?
b.
What is the probability that the guitar neck can be carved betwe
a.
.6875
b.
.875
c.
150
d.
23.09
Scores on a recent national statistics exam were normally distributed with a mean of 80 and a standard deviation of 6.
a.
What is the probability that a randomly selected exam will have a score of at least 71?
b.
What percentage of exams will have scores
a.
.9332
b.
.04
c.
91.76
d.
5000
The average starting salary of this year's MBA students is $35,000 with a standard deviation of $5,000. Furthermore, it is known that the starting salaries are normally distributed. What are the minimum and the maximum starting salaries of the middle 95%
Min. = 25,200; Max. = 44,800
The average starting salary for this year's graduates at a large university (LU) is $20,000 with a standard deviation of $8,000. Furthermore, it is known that the starting salaries are normally distributed.
a.
What is the probability that a randomly selec
a.
0.0968
b.
29.12
c.
35,680
d.
3000
DRUGS R US" is a large manufacturer of various kinds of liquid vitamins. The quality control department has noted that the bottles of vitamins marked 6 ounces vary in content with a standard deviation of 0.3 ounces. Assume the contents of the bottles are
a.
4.46%
b.
2.56%
c.
91.46%
d.
5.5065 ounces
e.
13.59%
The Globe Fishery packs shrimp that weigh more than 1.91 ounces each in packages marked" large" and shrimp that weigh less than 0.47 ounces each into packages marked "small"; the remainder are packed in "medium" size packages. If a day's catch showed that
Mean = 1.4 Standard deviation = 0.6
The monthly earnings of computer programmers are normally distributed with a mean of $4,000. If only 1.7 percent of programmers have monthly incomes of less than $2,834, what is the value of the standard deviation of the monthly earnings of the computer p
$550
A major department store has determined that its customers charge an average of $500 per month, with a standard deviation of $80. Assume the amounts of charges are normally distributed.
a.
What percentage of customers charges more than $380 per month?
b.
a.
93.32%
b.
2.28%
c.
2.97%
The First National Mortgage Company has noted that 6% of its customers pay their mortgage payments after the due date.
a.
What is the probability that in a random sample of 150 customers 7 will be late on their payments?
b.
What is the probability that in
a.
0.1066
b.
0.4325
The salaries of the employees of a corporation are normally distributed with a mean of $25,000 and a standard deviation of $5,000.
a.
What is the probability that a randomly selected employee will have a starting salary of at least $31,000?
b.
What percen
a.
0.1151
b.
0.52%
c.
minimum = $15,200 maximum = $34,800
d.
4,000
A manufacturing process produces items whose weights are normally distributed. It is known that 22.57% of all the items produced weigh between 100 grams up to the mean and 49.18% weigh from the mean up to 190 grams. Determine the mean and the standard dev
standard deviation = 30 mean = 113
The daily dinner bills in a local restaurant are normally distributed with a mean of $28 and a standard deviation of $6.
a.
What is the probability that a randomly selected bill will be at least $39.10?
b.
What percentage of the bills will be less than $1
a.
0.0322
b.
0.0322
c.
minimum = $16.24 maximum = $39.06
d.
2,000
The price of a bond is uniformly distributed between $80 and $85.
a.
What is the probability that the bond price will be at least $83?
b.
What is the probability that the bond price will be between $81 to $90?
c.
Determine the expected price of the bond.
a.
0.4
b.
0.8
c.
$82.50
d.
$1.44
18. The price of a stock is uniformly distributed between $30 and $40.
a.
What is the probability that the stock price will be more than $37?
b.
What is the probability that the stock price will be less than or equal to $32?
c.
What is the probability tha
a.
0.3
b.
0.2
c.
0.4
d.
$35
e.
$2.89
A random variable X is uniformly distributed between 45 and 150.
a.
Determine the probability of X = 48.
b.
What is the probability of X 60?
c.
What is the probability of X 50?
d.
Determine the expected vale of X and its standard deviation.
a.
0.000
b.
0.1429
c.
0.9524
d.
97.5, 30.31
The length of time patients must wait to see a doctor in a local clinic is uniformly distributed between 15 minutes and 2 1/2 hours.
a.
What is the probability of a patient waiting exactly 50 minutes?
b.
What is the probability that a patient would have t
a.
0.000
b.
0.556
c.
0.222
d.
82.5, 38.97
The monthly income of residents of Daisy City is normally distributed with a mean of $3000 and a standard deviation of $500.
a.
The mayor of Daisy City makes $2,250 a month. What percentage of Daisy City's residents has incomes that are more than the mayo
a.
93.32%
b.
2.12%
c.
Min = 2020 Max = 3980
d.
100,000
Z is a standard normal random variable. Compute the following probabilities.
a.
P(-1.33 Z 1.67)
b.
P(1.23 Z 1.55)
c.
P(Z 2.32)
d.
P(Z -2.08)
e.
P(Z -1.08)
a.
0.8607
b.
0.0487
c.
0.0102
d.
0.9812
e.
0.1401
The length of time it takes students to complete a statistics examination is uniformly distributed and varies between 40 and 60 minutes.
a.
Find the mathematical expression for the probability density function.
b.
Compute the probability that a student wi
ANS:
a.
f(x) = 0.05 for 40 x 60; zero elsewhere
b.
0.25
c.
0.00
d.
50 minutes
e.
33.33
The advertised weight on a can of soup is 10 ounces. The actual weight in the cans follows a uniform distribution and varies between 9.3 and 10.3 ounces.
a.
Give the mathematical expression for the probability density function.
b.
What is the probability
a.
f(x) = 1.000 for 9.3 x 10.3; zero elsewhere
b.
0.90
c.
9.8
d.
0.289
Z is a standard normal random variable. Compute the following probabilities.
a.
P(-1.23 Z 2.58)
b.
P(1.83 Z 1.96)
c.
P(Z 1.32)
d.
P(Z 2.52)
e.
P(Z -1.63)
f.
P(Z -1.38)
g.
P(-2.37 Z -1.54)
h.
P(Z = 2.56)
a.
0.8858
b.
0.0086
c.
0.0934
d.
0.9941
e.
0.9484
f.
0.0838
g.
0.0529
h.
The miles-per-gallon obtained by the 1995 model Z cars is normally distributed with a mean of 22 miles-per-gallon and a standard deviation of 5 miles-per-gallon.
a.
What is the probability that a car will get between 13.35 and 35.1 miles-per-gallon?
b.
Wh
a.
0.9538
b.
0.0643
c.
0.4207
d.
0.0000
The salaries at a corporation are normally distributed with an average salary of $19,000 and a standard deviation of $4,000.
a.
What is the probability that an employee will have a salary between $12,520 and $13,480?
b.
What is the probability that an emp
a.
0.0312
b.
0.9625
c.
0.9909
Z is a standard normal variable. Find the value of Z in the following.
a.
The area between 0 and Z is 0.4678.
b.
The area to the right of Z is 0.1112.
c.
The area to the left of Z is 0.8554
d.
The area between -Z and Z is 0.754.
e.
The area to the left of
a.
1.85
b.
1.22
c.
1.06
d.
1.16
e.
1.49
f.
2.06
The monthly earnings of computer systems analysts are normally distributed with a mean of $4,300. If only 1.07 percent of the systems analysts have a monthly income of more than $6,140, what is the value of the standard deviation of the monthly earnings o
$800
A major credit card company has determined that its customers charge an average of $280 per month on their accounts with a standard deviation of $20.
a.
What percentage of the customers charges more than $275 per month?
b.
What percentage of the customers
a.
59.87%
b.
3.22%
c.
83.43%
The ticket sales for events held at the new civic center are believed to be normally distributed with a mean of 12,000 and a standard deviation of 1,000.
a.
What is the probability of selling more than 10,000 tickets?
b.
What is the probability of selling
a.
0.9772
b.
0.1525
c.
0.0668
In a normal distribution, it is known that 27.34% of all the items are included from 100 up to the mean, and another 45.99% of all the items are included from the mean up to 145. Determine the mean and the standard deviation of the distribution.
Mean = 113.5 Standard deviation = 18
The records show that 8% of the items produced by a machine do not meet the specifications. Use the normal approximation to the binomial distribution to answer the following questions. What is the probability that a sample of 100 units contains
a.
Five or
a.
0.9015
b.
0.8212
c.
0.9015
Approximate the following binomial probabilities by the use of normal approximation.
a.
P(x < 12, n = 50, p = 0.3)
b.
P(12 < x < 18, n = 50, p = 0.3)
a.
0.2206
b.
0.7198
An airline has determined that 20% of its international flights are not on time. Use the normal approximation to the binomial distribution to answer the following questions. What is the probability that of the next 80 international flights
a.
Fifteen or l
a.
0.4443
b.
0.3372
c.
0.1071
The time it takes a mechanic to change the oil in a car is exponentially distributed with a mean of 5 minutes.
a.
What is the probability density function for the time it takes to change the oil?
b.
What is the probability that it will take a mechanic les
a.
f(x) =(1/5) e-x/5 for x 0
b.
0.6988
c.
0.1809
d.
0.25
The time it takes a worker on an assembly line to complete a task is exponentially distributed with a mean of 8 minutes.
a.
What is the probability density function for the time it takes to complete the task?
b.
What is the probability that it will take a
a.
f(x) =(1/8 ) e-x/8 for x > 0
b.
0.3935
c.
0.1859
For a standard normal distribution, determine the probability of obtaining a Z value of
a.
greater than zero.
b.
between -2.34 to -2.55
c.
less than 1.86.
d.
between -1.95 to 2.7.
e.
between 1.5 to 2.75.
a.
0.5000
b.
0.0042
c.
0.9686
d.
0.9709
e.
0.0638
The weights of items produced by a company are normally distributed with a mean of 4.5 ounces and a standard deviation of 0.3 ounces.
a.
What is the probability that a randomly selected item from the production will weigh at least 4.14 ounces?
b.
What per
a.
0.8849
b.
12.28%
c.
4.992
d.
625,000
The life expectancy of Timely brand watches is normally distributed with a mean of four years and a standard deviation of eight months.
a.
What is the probability that a randomly selected watch will be in working condition for more than five years?
b.
The
a.
0.0668
b.
93.32%
c.
Min = 32.32 months Max = 63.68 months
d.
34.84 months
The weights of the contents of cans of tomato sauce produced by a company are normally distributed with a mean of 8 ounces and a standard deviation of 0.2 ounces.
a.
What percentage of all cans produced contain more than 8.4 ounces of tomato paste?
b.
Wha
a.
2.28%
b.
15.87%
c.
97.58%
d.
7.671 oz
e.
13.59%
A professor at a local university noted that the grades of her students were normally distributed with a mean of 78 and a standard deviation of 10.
a.
The professor has informed us that 16.6 percent of her students received grades of A. What is the minimu
ANS:
a.
87.7
b.
66.3
c.
82.4
In grading eggs into small, medium, and large, the Nancy Farms packs the eggs that weigh more than 3.6 ounces in packages marked "large" and the eggs that weigh less than 2.4 ounces into packages marked "small"; the remainder are packed in packages marked
Mean = 3.092 Standard Deviation = 0.4
The weekly earnings of bus drivers are normally distributed with a mean of $395. If only 1.1 percent of the bus drivers have a weekly income of more than $429.35, what is the value of the standard deviation of the weekly earnings of the bus drivers?
Standard Deviation = 15
A local bank has determined that the daily balances of the checking accounts of its customers are normally distributed with an average of $280 and a standard deviation of $20.
a.
What percentage of its customers has daily balances of more than $275?
b.
Wh
a.
59.87%
b.
3.22%
c.
83.43%
The contents of soft drink bottles are normally distributed with a mean of twelve ounces and a standard deviation of one ounce.
a.
What is the probability that a randomly selected bottle will contain more than ten ounces of soft drink?
b.
What is the prob
a.
0.9772
b.
0.1525
c.
6.68%
The time between arrivals of customers at the drive-up window of a bank follows an exponential probability distribution with a mean of 10 minutes.
a.
What is the probability that the arrival time between customers will be 7 minutes or less?
b.
What is the
a.
0.5034
b.
0.2442
The time required to assemble a part of a machine follows an exponential probability distribution with a mean of 14 minutes.
a.
What is the probability that the part can be assembled in 7 minutes or less?
b.
What is the probability that the part can be as
a.
0.3935
b.
0.1723
The time it takes to completely tune an engine of an automobile follows an exponential distribution with a mean of 40 minutes.
a.
What is the probability of tuning an engine in 30 minutes or less?
b.
What is the probability of tuning an engine between 30
a.
0.5276
b.
0.0555
The life expectancy of computer terminals is normally distributed with a mean of 4 years and a standard deviation of 10 months.
a.
What is the probability that a randomly selected terminal will last more than 5 years?
b.
What percentage of terminals will
a.
0.1151
b.
10.69%
c.
50%
d.
68.98%
e.
11.51%
Approximate the following binomial probabilities by the use of normal approximation. Twenty percent of students who finish high school do not go to college. What is the probability that in a sample of 80 high school students
a.
exactly 10 will not go to c
a.
0.0274
b.
0.0618
c.
0.3372
Approximate the following binomial probabilities by the use of normal approximation. Eight percent of customers of a bank keep a minimum balance of $500 in their checking accounts. What is the probability that in a random sample of 100 customers
a.
exactl
a.
0.1124
b.
0.0803
c.
0.2912
d.
0.9015
e.
0.8212
f.
0.9015
Approximate the following binomial probabilities by the use of normal approximation.
a.
P(X = 18, n = 50, p = 0.3)
b.
P(X 15, n = 50, p = 0.3)
c.
P(X 12, n = 50, p = 0.3)
d.
P(12 X 18, n = 50, p = 0.3)
a.
0.0805
b.
0.5596
c.
0.2206
d.
0.7198
Twenty percent of the employees of a large company are female. Use the normal approximation of the binomial probabilities to answer the following questions. What is the probability that in a random sample of 80 employees
a.
exactly 16 will be female?
b.
1
a.
0.1114
b.
0.7580
c.
0.4443
d.
0.3372
e.
0.1071
The average life expectancy of dishwashers produced by a company is 6 years with a standard deviation of 8 months. Assume that the lives of dishwashers are normally distributed.
a.
What is the probability that a randomly selected dishwasher will have a li
a.
0.0668
b.
1.22%
c.
56.32 and 87.68 (Months)
d.
25,000