Question 1

Which of the following properties distinguishes the standard normal distribution from other normal distributions?

Accepted Answer

A)  The mean is 0 and the standard deviation is 1. 
B)  The total area under the curve is equal to 1.00. 
C)  The curve is continuous. 
D)  The mean is located at the center of the distribution. 
A)  The mean is 0 and the standard deviation is 1. 
B)  The total area under the curve is equal to 1.00. 
C)  The curve is continuous. 
D)  The mean is located at the center of the distribution. A

Question 2

The mean weight of loads of rock is 47.0 tons with a standard deviation of 6.0 tons. If 16 loads are chosen at random for a weight check, find the probability that the mean weight of those loads is less than 46.2 tons. Assume that the variable is normally distributed.

Accepted Answer

A)  21.23 
B)  28.77 
C)  71.23 
D)  78.77 
A)  21.23 
B)  28.77 
C)  71.23 
D)  78.77 B

Question 3

Identify the type of distribution pattern that occurs when the majority of the data values fall to the left of the mean?

Accepted Answer

A)  symmetrical 
B)  positively skewed 
C)  negatively skewed 
D)  left skewed 
A)  symmetrical 
B)  positively skewed 
C)  negatively skewed 
D)  left skewed B

Question 4

If a baseball player's batting average is 0.340 , find the probability that the player will have a bad season and get at most 60 hits in 200 times at bat?

Accepted Answer

A)  38.3% 
B)  11.7% 
C)  36.9% 
D)  13.1% 
A)  38.3% 
B)  11.7% 
C)  36.9% 
D)  13.1%

Question 5

A survey of 250 lobster fishermen found that they catch an average of 32.0 pounds of lobster per day with a standard deviation of 4.0 pounds. If a random sample of 36 lobster fishermen is selected, what is the probability that their average catch is less than 31.5 pounds? Assume the distribution of the weights of lobster is normal.

Accepted Answer

The answer of A survey of 250 lobster fishermen found...

Question 6

X is a normally distributed random variable with a mean of 5.0. Find the standard deviation of the distribution if 59.10% of the data lies to the right of 4.54. (Note: the diagram is not necessarily to scale.)

Accepted Answer

A)  2.0 
B)  1.3 
C)  1.0 
D)  0.5 
A)  2.0 
B)  1.3 
C)  1.0 
D)  0.5

Question 7

When the data values are evenly distributed about the mean, the distribution is said to be ______________.

Accepted Answer

The answer of When the data values are evenly distributed...

Question 8

The area under the normal distribution curve that lies within three standard deviations of the mean is approximately 95%.

Accepted Answer

A) True 
 B)False

Question 9

The average height of flowering cherry trees in a certain nursery is 10.5 feet. If the heights are normally distributed with a standard deviation of 1.5 feet, find the probability that a tree is less than 12.5 feet tall.

Accepted Answer

A)  0.73 
B)  0.91 
C)  0.96 
D)  0.82 
A)  0.73 
B)  0.91 
C)  0.96 
D)  0.82

Question 10

Which choice is another term that can be used to describe a normal distribution:

Accepted Answer

A)  independent variable 
B)  discrete distribution 
C)  negatively or positively skewed 
D)  bell curve 
A)  independent variable 
B)  discrete distribution 
C)  negatively or positively skewed 
D)  bell curve

Question 11

Find the probability   , using the standard normal distribution.

Accepted Answer

A)  45.25% 
B)  45.54% 
C)  42.07% 
D)  35.54% 
A)  45.25% 
B)  45.54% 
C)  42.07% 
D)  35.54%

Question 12

On an easy test, the mean score was 98 out of a possible 100 points. The distribution of the test scores is likely to be

Accepted Answer

A)  symmetric. 
B)  negatively skewed. 
C)  positively skewed. 
D)  diagonally skewed. 
A)  symmetric. 
B)  negatively skewed. 
C)  positively skewed. 
D)  diagonally skewed.

Question 13

What is the area under the standard normal distribution curve between z = 1.50 and z = 2.50?

Accepted Answer

A)  0.0802 
B)  0.0606 
C)  0.0764 
D)  1.00 
A)  0.0802 
B)  0.0606 
C)  0.0764 
D)  1.00

Question 14

If the standard deviation of a normally distributed population is 60.0 and we take a sample of size 25, then the standard error of the mean is

Accepted Answer

A)  12.0 
B)  5.0 
C)  60.0 
D)  2.4 
A)  12.0 
B)  5.0 
C)  60.0 
D)  2.4

Question 15

The average number of mosquitos in a stagnant pond is 60 per square meter with a standard deviation of 16. If 25 square meters are chosen at random for a mosquito count, find the probability that the average of those counts is more than 62.9 mosquitos per square meter. Assume that the variable is normally distributed.

Accepted Answer

A)  0.3% 
B)  18.4% 
C)  31.6% 
D)  81.6% 
A)  0.3% 
B)  18.4% 
C)  31.6% 
D)  81.6%

Question 16

The standard deviation of sample means will be larger than the standard deviation of the population.

Accepted Answer

A) True 
 B)False

Question 17

The following formula can be used to find the specific value of the variable in a data set that corresponds to a particular value of the standard normal variable:

Accepted Answer

A) True 
 B)False

Question 18

Find the area under the standard normal distribution curve to the left of z = 1.69.

Accepted Answer

A)  0.4545 
B)  0.4452 
C)  0.9545 
D)  0.9452 
A)  0.4545 
B)  0.4452 
C)  0.9545 
D)  0.9452

Question 19

Use the normal approximation to the binomial to find that probability for the specific value of X.
N = 20, p = 0.3, X = 7

Accepted Answer

A)  0.17 
B)  0.35 
C)  0.11 
D)  0.3 
A)  0.17 
B)  0.35 
C)  0.11 
D)  0.3

Question 20

Find the probability   using the standard normal distribution.

Accepted Answer

A)  0.2517 
B)  0.7517 
C)  0.7483 
D)  0.2483 
A)  0.2517 
B)  0.7517 
C)  0.7483 
D)  0.2483

Which of the following properties distinguishes the standard normal distribution from other normal distributions?

The mean weight of loads of rock is 47.0 tons with a standard deviation of 6.0 tons. If 16 loads are chosen at random for a weight check, find the probability that the mean weight of those loads is less than 46.2 tons. Assume that the variable is normally distributed.

Identify the type of distribution pattern that occurs when the majority of the data values fall to the left of the mean?

If a baseball player's batting average is 0.340 , find the probability that the player will have a bad season and get at most 60 hits in 200 times at bat?

X is a normally distributed random variable with a mean of 5.0. Find the standard deviation of the distribution if 59.10% of the data lies to the right of 4.54. (Note: the diagram is not necessarily to scale.)

When the data values are evenly distributed about the mean, the distribution is said to be ______________.

The area under the normal distribution curve that lies within three standard deviations of the mean is approximately 95%.

The average height of flowering cherry trees in a certain nursery is 10.5 feet. If the heights are normally distributed with a standard deviation of 1.5 feet, find the probability that a tree is less than 12.5 feet tall.

Which choice is another term that can be used to describe a normal distribution:

Find the probability , using the standard normal distribution.

On an easy test, the mean score was 98 out of a possible 100 points. The distribution of the test scores is likely to be

What is the area under the standard normal distribution curve between z = 1.50 and z = 2.50?

If the standard deviation of a normally distributed population is 60.0 and we take a sample of size 25, then the standard error of the mean is

The standard deviation of sample means will be larger than the standard deviation of the population.

The following formula can be used to find the specific value of the variable in a data set that corresponds to a particular value of the standard normal variable:

Find the area under the standard normal distribution curve to the left of z = 1.69.

Use the normal approximation to the binomial to find that probability for the specific value of X. N = 20, p = 0.3, X = 7

Find the probability using the standard normal distribution.

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Probability and Counting Rules

Discrete Probability Distributions

Confidence Intervals and Sample Size

Hypothesis Testing

Testing the Difference Between Two Means, Two Variances, and Two Proportions

Correlation and Regression

Other Chi-Square Tests

Analysis of Variance

Nonparametric Statistics

Sampling and Simulation

Filters

Exam 6: The Normal Distribution

Which of the following properties distinguishes the standard normal distribution from other normal distributions?

The mean weight of loads of rock is 47.0 tons with a standard deviation of 6.0 tons. If 16 loads are chosen at random for a weight check, find the probability that the mean weight of those loads is less than 46.2 tons. Assume that the variable is normally distributed.

Identify the type of distribution pattern that occurs when the majority of the data values fall to the left of the mean?

If a baseball player's batting average is 0.340 , find the probability that the player will have a bad season and get at most 60 hits in 200 times at bat?

X is a normally distributed random variable with a mean of 5.0. Find the standard deviation of the distribution if 59.10% of the data lies to the right of 4.54. (Note: the diagram is not necessarily to scale.)

When the data values are evenly distributed about the mean, the distribution is said to be ______________.

The area under the normal distribution curve that lies within three standard deviations of the mean is approximately 95%.

The average height of flowering cherry trees in a certain nursery is 10.5 feet. If the heights are normally distributed with a standard deviation of 1.5 feet, find the probability that a tree is less than 12.5 feet tall.

Which choice is another term that can be used to describe a normal distribution:

Find the probability , using the standard normal distribution.

On an easy test, the mean score was 98 out of a possible 100 points. The distribution of the test scores is likely to be

What is the area under the standard normal distribution curve between z = 1.50 and z = 2.50?

If the standard deviation of a normally distributed population is 60.0 and we take a sample of size 25, then the standard error of the mean is

The standard deviation of sample means will be larger than the standard deviation of the population.

The following formula can be used to find the specific value of the variable in a data set that corresponds to a particular value of the standard normal variable:

Find the area under the standard normal distribution curve to the left of z = 1.69.

Use the normal approximation to the binomial to find that probability for the specific value of X. N = 20, p = 0.3, X = 7

Find the probability using the standard normal distribution.

The Nature of Probability and Statistics

Frequency Distributions and Graphs

Data Description

Probability and Counting Rules

Discrete Probability Distributions

Confidence Intervals and Sample Size

Hypothesis Testing

Testing the Difference Between Two Means, Two Variances, and Two Proportions

Correlation and Regression

Other Chi-Square Tests

Analysis of Variance

Nonparametric Statistics

Sampling and Simulation

Filters