Question 1

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

Accepted Answer

A) 70.00 
B) 74.69 
C) 65.31 
D) 75.25

Question 2

The uniform probability distribution's standard deviation is proportional to the distribution's range.

Accepted Answer

A) True 
 B)False

Question 3

The number of different normal distributions is unlimited.

Accepted Answer

A) True 
 B)False

Question 4

In a standard normal distribution,µ = ______ and $\sigma$= ______.

Accepted Answer

The answer of In a standard normal distribution,µ = ______...

Question 5

The seasonal output of a new experimental strain of pepper plants was carefully weighed.The mean weight per plant is 15.0 pounds,and the standard deviation of the normally distributed weights is 1.75 pounds.Of the 200 plants in the experiment,how many produced peppers weighing between 13 and 16 pounds?

Accepted Answer

A) 100 
B) 118 
C) 197 
D) 53

Question 6

A z-score is the distance between a selected value (X)and the population mean (µ)divided by the population standard deviation ($\sigma$).

Accepted Answer

A) True 
 B)False

Question 7

What is the proportion of the total area under the normal curve within plus and minus two standard deviations of the mean?

Accepted Answer

A) 68% 
B) 99.7% 
C) 34% 
D) 95%

Question 8

A cola-dispensing machine is set to dispense a mean of 2.02 liters into a container labeled 2 liters.Actual quantities dispensed vary and the amounts are normally distributed with a standard deviation of 0.015 liters.What is the probability a container will have less than 2 liters?

Accepted Answer

A) 0.0918 
B) 0.3413 
C) 0.1926 
D) 0.8741

Question 9

Which student scored better compared to the rest of the section? _______________

Accepted Answer

The answer of Which student scored better compared to the...

Question 10

Non-stop Airlines determined that the mean number of passengers per flight is 152 with a standard deviation of ten passengers.Practically all flights have between 142 and 162 passengers.

Accepted Answer

A) True 
 B)False

Question 11

The annual commissions per salesperson employed by a manufacturer of light machinery averaged $40,000 with a standard deviation of $5,000.What percent of the sales persons earn between $32,000 and $42,000?

Accepted Answer

A) 60.06% 
B) 39.94% 
C) 34.13% 
D) 81.66%

Question 12

Two normal distributions are compared.One has a mean of 10 and a standard deviation of 10.The second normal distribution has a mean of 10 and a standard deviation of 2.Which of the following is true?

Accepted Answer

A) The locations of the distributions are different 
B) The distributions are from two different families of distributions 
C) The dispersions of the distributions are different 
D) The dispersions of the distributions are the same

Question 13

The standard normal probability distribution is unique because it has:

Accepted Answer

A) A mean of 1 and any standard deviation 
B) Any mean and a standard deviation of 1 
C) A mean of 0 and any standard deviation 
D) A mean of 0 and a standard deviation of 1

Question 14

The distribution of the annual incomes of a group of middle management employees approximated a normal distribution with a mean of $37,200 and a standard deviation of $800.About 68 percent of the incomes lie between what two incomes?

Accepted Answer

A) $30,000 and $40,000 
B) $36,400 and $38,000 
C) $34,800 and $39,600 
D) $35,600 and $38,800

Question 15

For the normal distribution,the mean plus and minus 1.96 standard deviations will include about what percent of the observations?

Accepted Answer

A) 50% 
B) 99.7% 
C) 95% 
D) 68%

Question 16

The mean of a normal distribution is represented by $\sigma$.

Accepted Answer

A) True 
 B)False

Question 17

The uniform probability distribution is symmetric about the mode.

Accepted Answer

A) True 
 B)False

Question 18

When referring to the normal probability distribution,there is not just one;there is a "family" of distributions.

Accepted Answer

A) True 
 B)False

Question 19

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what is the probability that a student scored 90 or higher?

Accepted Answer

A) 0.4979 
B) 0.0021 
C) 0.9979 
D) 2.86

Question 20

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

Accepted Answer

A) True 
 B)False

Exam 7: Continuous Probability Distributions

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

The uniform probability distribution's standard deviation is proportional to the distribution's range.

The number of different normal distributions is unlimited.

In a standard normal distribution,µ = and $\sigma$ = .

A z-score is the distance between a selected value (X)and the population mean (µ)divided by the population standard deviation ( $\sigma$ ).

What is the proportion of the total area under the normal curve within plus and minus two standard deviations of the mean?

A cola-dispensing machine is set to dispense a mean of 2.02 liters into a container labeled 2 liters.Actual quantities dispensed vary and the amounts are normally distributed with a standard deviation of 0.015 liters.What is the probability a container will have less than 2 liters?

Which student scored better compared to the rest of the section? _______________

Non-stop Airlines determined that the mean number of passengers per flight is 152 with a standard deviation of ten passengers.Practically all flights have between 142 and 162 passengers.

The annual commissions per salesperson employed by a manufacturer of light machinery averaged $40,000 with a standard deviation of $5,000.What percent of the sales persons earn between $32,000 and $42,000?

Two normal distributions are compared.One has a mean of 10 and a standard deviation of 10.The second normal distribution has a mean of 10 and a standard deviation of 2.Which of the following is true?

The standard normal probability distribution is unique because it has:

The distribution of the annual incomes of a group of middle management employees approximated a normal distribution with a mean of $37,200 and a standard deviation of $800.About 68 percent of the incomes lie between what two incomes?

For the normal distribution,the mean plus and minus 1.96 standard deviations will include about what percent of the observations?

The mean of a normal distribution is represented by $\sigma$ .

The uniform probability distribution is symmetric about the mode.

When referring to the normal probability distribution,there is not just one;there is a "family" of distributions.

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what is the probability that a student scored 90 or higher?

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

Exam 7: Continuous Probability Distributions

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what test score separates the top 25% of the students from the lower 75% of students?

The uniform probability distribution's standard deviation is proportional to the distribution's range.

The number of different normal distributions is unlimited.

In a standard normal distribution,µ = ______ and σ\sigmaσ = ______.

A z-score is the distance between a selected value (X)and the population mean (µ)divided by the population standard deviation ( σ\sigmaσ ).

What is the proportion of the total area under the normal curve within plus and minus two standard deviations of the mean?

A cola-dispensing machine is set to dispense a mean of 2.02 liters into a container labeled 2 liters.Actual quantities dispensed vary and the amounts are normally distributed with a standard deviation of 0.015 liters.What is the probability a container will have less than 2 liters?

Which student scored better compared to the rest of the section? _______________

Non-stop Airlines determined that the mean number of passengers per flight is 152 with a standard deviation of ten passengers.Practically all flights have between 142 and 162 passengers.

The annual commissions per salesperson employed by a manufacturer of light machinery averaged $40,000 with a standard deviation of $5,000.What percent of the sales persons earn between $32,000 and $42,000?

Two normal distributions are compared.One has a mean of 10 and a standard deviation of 10.The second normal distribution has a mean of 10 and a standard deviation of 2.Which of the following is true?

The standard normal probability distribution is unique because it has:

The distribution of the annual incomes of a group of middle management employees approximated a normal distribution with a mean of $37,200 and a standard deviation of $800.About 68 percent of the incomes lie between what two incomes?

For the normal distribution,the mean plus and minus 1.96 standard deviations will include about what percent of the observations?

The mean of a normal distribution is represented by σ\sigmaσ .

The uniform probability distribution is symmetric about the mode.

When referring to the normal probability distribution,there is not just one;there is a "family" of distributions.

The average score of 100 students taking a statistics final was 70 with a standard deviation of 7.Assuming a normal distribution,what is the probability that a student scored 90 or higher?

The standard normal distribution is a special normal distribution with a mean of 0 and a standard deviation of 1.

In a standard normal distribution,µ = and $\sigma$ = .

A z-score is the distance between a selected value (X)and the population mean (µ)divided by the population standard deviation ( $\sigma$ ).

The mean of a normal distribution is represented by $\sigma$ .