AP Stats Unit 5 MCQ A Revision Exam
Questions With Actual Solutions.
The distribution of heights for adult men in a certain population is approximately normal with
mean 70 inches and standard deviation 4 inches. Which of the following represents the middle
80 percent of the heights?
A.) 50 inches to 73.37 inches
B.) 62 inches to 78 inches
C.) 64.87 inches to 75.13 inches
D.) 66 inches to 74 inches
E.) 66.63 inches to 90 inches - Answer C.) 64.87 inches to 75.13 inches
The distribution of the amount of water used per wash cycle, in gallons, by a particular brand of
dishwasher during a wash cycle is approximately normal with mean 4 gallons and standard
deviation 0.2 gallon. Which of the following is closest to the probability that more than 3.75
gallons are used for any wash cycle?
A.) 0.11
B.) 0.21
C.) 0.34
D.) 0.79
E.) 0.89 - Answer E.) 0.89
The life span of a battery is the amount of time the battery will last. The distribution of life span
for a certain type of battery is approximately normal with mean 2.5 hours and standard
deviation 0.25 hour. Suppose one battery will be selected at random. Which of the following is
closest to the probability that the selected battery will have a life span of at most 2.1 hours?
A.) 0.055
B.) 0.110
C.) 0.445
D.) 0.890
, A.) The distribution of heights of tomato plants growing at an agricultural center, where most
heights cluster around the center and there are some very short and very tall heights.
B.) The distribution of times that a certain brand of house paint lasts on a house, where the
distribution is symmetric and bell-shaped.
C.) The distribution of lengths of the trout living in a certain stream, where the distribution is
unimodal and clustered around the center, and the left half is a mirror image of the right half.
D.) The distribution of weights of mold samples growing in a laboratory, where the distribution
is symmetric, unimodal, and does not have any outliers.
E.) The distribution of ages, in years, of all the residents of a town, where the right tail of the
distribution is longer than the left. - Answer E.) The distribution of ages, in years, of all the
residents of a town, where the right tail of the distribution is longer than the left.
Felip recorded 75 numerical observations on a certain variable and then calculated the mean x¯
and the standard deviation s for the observations. To help decide whether a normal model is
appropriate, he created the following chart.
In Felip's chart, the letters a,b,c,d,e represents the number of observations falling in each
interval. Which of the following lists of counts for a,b,c,d,e, respectively, is the best indicator
that the variable can be modeled with a normal approximation?
A.) 1, 31, 11, 31, 1
B.) 2, 10, 51, 10, 2
C.) 3, 6, 12, 24, 30
D.) 40, 20, 10, 4, 1
E.) 15, 15, 15, 15, 15 - Answer B.) 2, 10, 51, 10, 2
The mean and standard deviation of the sample data collected on continuous variable YY are
−0.5−0.5 and 0.5, respectively. The following table shows the relative frequencies of the data in
the given intervals.
Based on the table, is it appropriate to use the normal model to approximate the population
distribution?
A.) Yes, because the sum of the relative frequencies is 1.00.
B.) Yes, because the distribution of relative frequencies indicates a symmetric distribution.
C.) No, because the value of 0 is not in the center of the distribution.
Questions With Actual Solutions.
The distribution of heights for adult men in a certain population is approximately normal with
mean 70 inches and standard deviation 4 inches. Which of the following represents the middle
80 percent of the heights?
A.) 50 inches to 73.37 inches
B.) 62 inches to 78 inches
C.) 64.87 inches to 75.13 inches
D.) 66 inches to 74 inches
E.) 66.63 inches to 90 inches - Answer C.) 64.87 inches to 75.13 inches
The distribution of the amount of water used per wash cycle, in gallons, by a particular brand of
dishwasher during a wash cycle is approximately normal with mean 4 gallons and standard
deviation 0.2 gallon. Which of the following is closest to the probability that more than 3.75
gallons are used for any wash cycle?
A.) 0.11
B.) 0.21
C.) 0.34
D.) 0.79
E.) 0.89 - Answer E.) 0.89
The life span of a battery is the amount of time the battery will last. The distribution of life span
for a certain type of battery is approximately normal with mean 2.5 hours and standard
deviation 0.25 hour. Suppose one battery will be selected at random. Which of the following is
closest to the probability that the selected battery will have a life span of at most 2.1 hours?
A.) 0.055
B.) 0.110
C.) 0.445
D.) 0.890
, A.) The distribution of heights of tomato plants growing at an agricultural center, where most
heights cluster around the center and there are some very short and very tall heights.
B.) The distribution of times that a certain brand of house paint lasts on a house, where the
distribution is symmetric and bell-shaped.
C.) The distribution of lengths of the trout living in a certain stream, where the distribution is
unimodal and clustered around the center, and the left half is a mirror image of the right half.
D.) The distribution of weights of mold samples growing in a laboratory, where the distribution
is symmetric, unimodal, and does not have any outliers.
E.) The distribution of ages, in years, of all the residents of a town, where the right tail of the
distribution is longer than the left. - Answer E.) The distribution of ages, in years, of all the
residents of a town, where the right tail of the distribution is longer than the left.
Felip recorded 75 numerical observations on a certain variable and then calculated the mean x¯
and the standard deviation s for the observations. To help decide whether a normal model is
appropriate, he created the following chart.
In Felip's chart, the letters a,b,c,d,e represents the number of observations falling in each
interval. Which of the following lists of counts for a,b,c,d,e, respectively, is the best indicator
that the variable can be modeled with a normal approximation?
A.) 1, 31, 11, 31, 1
B.) 2, 10, 51, 10, 2
C.) 3, 6, 12, 24, 30
D.) 40, 20, 10, 4, 1
E.) 15, 15, 15, 15, 15 - Answer B.) 2, 10, 51, 10, 2
The mean and standard deviation of the sample data collected on continuous variable YY are
−0.5−0.5 and 0.5, respectively. The following table shows the relative frequencies of the data in
the given intervals.
Based on the table, is it appropriate to use the normal model to approximate the population
distribution?
A.) Yes, because the sum of the relative frequencies is 1.00.
B.) Yes, because the distribution of relative frequencies indicates a symmetric distribution.
C.) No, because the value of 0 is not in the center of the distribution.
