Question 1

Find the area under the standard normal curve over the interval specified below. To the left of z = 0

Accepted Answer

A) 0.999 
B) 0.500 
C) 0.023 
D) 0.977 
E) 0.159 
A) 0.999 
B) 0.500 
C) 0.023 
D) 0.977 
E) 0.159

Question 2

What is a statistic?

Accepted Answer

A) A conclusion about the value of a population parameter based on information about the corresponding sample statistic and probability 
B) A numerical descriptive measure of a population 
C) A set of measurements (or counts), either existing or conceptual 
D) A probability distribution for a sample statistic 
E) A numerical descriptive measure of a sample 
A) A conclusion about the value of a population parameter based on information about the corresponding sample statistic and probability 
B) A numerical descriptive measure of a population 
C) A set of measurements (or counts), either existing or conceptual 
D) A probability distribution for a sample statistic 
E) A numerical descriptive measure of a sample

Question 3

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(z $\ge$  -0.9)

Accepted Answer

A) 0.816 
B) 0.092 
C) 0.158 
D) 0.184 
E) 0.316 
A) 0.816 
B) 0.092 
C) 0.158 
D) 0.184 
E) 0.316

Question 4

Suppose a certain species of fawns between 1 and 5 months old have a body weight that is approximately normally distributed with mean $\mu$= 21.1 kilograms and standard deviation $\sigma$= 3.7 kilograms. Let x be the weight of a fawn in kilograms. Convert the following z interval to a x interval. $$- 3.1 < z$$

Accepted Answer

A) x  9.63 
D) x > 32.57 
E) x > -32.57 
A) x  9.63 
D) x > 32.57 
E) x > -32.57

Question 5

Find z such that 22.4% of the standard normal curve lies to the right of z.

Accepted Answer

A) 0.759 
B) -0.285 
C) 0.285 
D) 0.595 
E) -0.759 
A) 0.759 
B) -0.285 
C) 0.285 
D) 0.595 
E) -0.759

Question 6

Select the graph corresponding to the following statement. 6.7% of the standard normal curve lies to the left of z.

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 7

Find z such that 24.1% of the standard normal curve lies to the left of z.

Accepted Answer

A) 1.169 
B) 0.646 
C) -0.703 
D) -0.646 
E) 0.703 
A) 1.169 
B) 0.646 
C) -0.703 
D) -0.646 
E) 0.703

Question 8

Assume that about 45% of all U.S. adults try to pad their insurance claims. Suppose that you are the director of an insurance adjustment office. Your office has just received 102 insurance claims to be processed in the next few days. What is the probability that more than 49 of the claims are not padded?

Accepted Answer

A) 0.947 
B) 0.957 
C) 0.906 
D) 0.888 
E) 0.065 
A) 0.947 
B) 0.957 
C) 0.906 
D) 0.888 
E) 0.065

Question 9

Suppose that about 25% of ice cream sales are vanilla and that about 8% of ice cream sales are chocolate. A customer who buys ice cream is not limited to one container or one flavor. What is the probability that someone who is buying ice cream will buy chocolate or vanilla? [Hint: Use the probability of success.]

Accepted Answer

A) 0.330 
B) 0.310 
C) 0.020 
D) 0.080 
E) 0.350 
A) 0.330 
B) 0.310 
C) 0.020 
D) 0.080 
E) 0.350

Question 10

Suppose a certain species of fawns between 1 and 5 months old have a body weight that is approximately normally distributed with mean $\mu$ = 22.4 kilograms and standard deviation $\sigma$= 4.9 kilograms. Let x be the weight of a fawn in kilograms. Convert the following x interval to a z interval. Round to the nearest hundredth. $$x < 36.1$$

Accepted Answer

A) z > -2.80 
B) z  2.80 
A) z > -2.80 
B) z  2.80

Question 11

Let x = red blood cell (RBC) count in millions per cubic millimeter of whole blood. Suppose that for healthy females, x has an approximately normal distribution with mean $\mu$= 4.7 and standard deviation $\sigma$= 0.3 Convert the following x interval from a laboratory test to a z interval. 4.0 < x < 5.5

Accepted Answer

A) 11.67 < z < 14.00 
B) -4.00 < z < 14.00 
C) -4.00 < z < -1.67 
D) 11.67 < z < 29.67 
E) 14.00 < z < 27.33 
A) 11.67 < z < 14.00 
B) -4.00 < z < 14.00 
C) -4.00 < z < -1.67 
D) 11.67 < z < 29.67 
E) 14.00 < z < 27.33

Question 12

Assume that about 30% of all U.S. adults try to pad their insurance claims. Suppose that you are the director of an insurance adjustment office. Your office has just received 132 insurance claims to be processed in the next few days. What is the probability that from 31 to 47 of the claims have been padded?

Accepted Answer

A) 0.843 
B) 0.891 
C) 0.871 
D) 0.899 
E) 0.911 
A) 0.843 
B) 0.891 
C) 0.871 
D) 0.899 
E) 0.911

Question 13

Find the area under the standard normal curve over the interval specified below. Between z = 0.8 and z = 1.9

Accepted Answer

A) -0.759 
B) 0.029 
C) 0.471 
D) 0.212 
E) 0.183 
A) -0.759 
B) 0.029 
C) 0.471 
D) 0.212 
E) 0.183

Question 14

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(-1.7 $\le$ z $\le$-0.8)

Accepted Answer

A) 0.816 
B) 0.167 
C) 0.212 
D) 0.788 
E) 0.955 
A) 0.816 
B) 0.167 
C) 0.212 
D) 0.788 
E) 0.955

Question 15

The incubation time for Rhode Island Red chicks is normally distributed with mean of 30 days and standard deviation of approximately 2 days. If 1000 eggs are being incubated, how many chicks do we expect will hatch in 26 to 36 days?

Accepted Answer

A) 976 chicks 
B) 477 chicks 
C) 21 chicks 
D) 157 chicks 
E) 136 chicks 
A) 976 chicks 
B) 477 chicks 
C) 21 chicks 
D) 157 chicks 
E) 136 chicks

Question 16

Suppose that about 62% of the people who are murdered actually knew the person who committed the murder. Suppose that a detective file in Boston has 62 current unsolved murders. What is the probability that fewer than 33 victims did not know their murderer?

Accepted Answer

A) 0.995 
B) 0.007 
C) 0.993 
D) 0.010 
E) 0.990 
A) 0.995 
B) 0.007 
C) 0.993 
D) 0.010 
E) 0.990

Question 17

What is a parameter?

Accepted Answer

A) A conclusion about the value of a population parameter based on information about the corresponding sample statistic and probability 
B) A numerical descriptive measure of a population 
C) A set of measurements (or counts), either existing or conceptual 
D) A probability distribution for a sample statistic 
E) A numerical descriptive measure of a sample 
A) A conclusion about the value of a population parameter based on information about the corresponding sample statistic and probability 
B) A numerical descriptive measure of a population 
C) A set of measurements (or counts), either existing or conceptual 
D) A probability distribution for a sample statistic 
E) A numerical descriptive measure of a sample

Question 18

At a certain excavation site, archaeological studies have used the method of tree-ring dating in an effort to determine when people lived in there. Wood from several excavations gave a mean of (year) 899 with a standard deviation of 38 years. The distribution of dates was more or less mound-shaped and symmetrical about the mean. Use the empirical rule to estimate a range of years centered about the mean in which about 68.3% of the data (tree-ring dates) will be found.

Accepted Answer

A) from 975 to 1013 
B) from 861 to 1013 
C) from 899 to 1013 
D) from 785 to 861 
E) from 861 to 937 
A) from 975 to 1013 
B) from 861 to 1013 
C) from 899 to 1013 
D) from 785 to 861 
E) from 861 to 937

Question 19

Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities. P(1 $\le$ x $\le$18)$\mu$ = 12;$\sigma$ = 4

Accepted Answer

A) 0.997 
B) 0.067 
C) 0.106 
D) 0.930 
E) 0.003 
A) 0.997 
B) 0.067 
C) 0.106 
D) 0.930 
E) 0.003

Question 20

The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that the average height of a sample of ten 18-year-old men will be between 67 and 68 inches? $$\bar { x }$$

Accepted Answer

A) 0.3531 
B) 0.6469 
C) 0.1469 
D) 0.7062 
E) 0.3961 
A) 0.3531 
B) 0.6469 
C) 0.1469 
D) 0.7062 
E) 0.3961

Find the area under the standard normal curve over the interval specified below. To the left of z = 0

What is a statistic?

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(z $\ge$ -0.9)

Find z such that 22.4% of the standard normal curve lies to the right of z.

Select the graph corresponding to the following statement. 6.7% of the standard normal curve lies to the left of z.

Find z such that 24.1% of the standard normal curve lies to the left of z.

Find the area under the standard normal curve over the interval specified below. Between z = 0.8 and z = 1.9

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(-1.7 $\le$ z $\le$ -0.8)

The incubation time for Rhode Island Red chicks is normally distributed with mean of 30 days and standard deviation of approximately 2 days. If 1000 eggs are being incubated, how many chicks do we expect will hatch in 26 to 36 days?

Suppose that about 62% of the people who are murdered actually knew the person who committed the murder. Suppose that a detective file in Boston has 62 current unsolved murders. What is the probability that fewer than 33 victims did not know their murderer?

What is a parameter?

Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities. P(1 $\le$ x $\le$ 18) $\mu$ = 12; $\sigma$ = 4

The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that the average height of a sample of ten 18-year-old men will be between 67 and 68 inches? $\bar { x }$

Getting Started

Organizing Data

Averages and Variation

Correlation and Regression

Elementary Probability Theory

The Binomial Probability Distribution and Related Topics

Estimation

Hypothesis Testing

Inferences About Differences

Additional Topics Using Inference

Filters

Exam 7: Normal Curves and Sampling Distributions

Find the area under the standard normal curve over the interval specified below. To the left of z = 0

What is a statistic?

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(z ≥\ge≥ -0.9)

Find z such that 22.4% of the standard normal curve lies to the right of z.

Select the graph corresponding to the following statement. 6.7% of the standard normal curve lies to the left of z.

Find z such that 24.1% of the standard normal curve lies to the left of z.

Find the area under the standard normal curve over the interval specified below. Between z = 0.8 and z = 1.9

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(-1.7 ≤\le≤ z ≤\le≤ -0.8)

The incubation time for Rhode Island Red chicks is normally distributed with mean of 30 days and standard deviation of approximately 2 days. If 1000 eggs are being incubated, how many chicks do we expect will hatch in 26 to 36 days?

Suppose that about 62% of the people who are murdered actually knew the person who committed the murder. Suppose that a detective file in Boston has 62 current unsolved murders. What is the probability that fewer than 33 victims did not know their murderer?

What is a parameter?

Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities. P(1 ≤\le≤ x ≤\le≤ 18) μ\muμ = 12; σ\sigmaσ = 4

The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that the average height of a sample of ten 18-year-old men will be between 67 and 68 inches? xˉ\bar { x }xˉ

Getting Started

Organizing Data

Averages and Variation

Correlation and Regression

Elementary Probability Theory

The Binomial Probability Distribution and Related Topics

Estimation

Hypothesis Testing

Inferences About Differences

Additional Topics Using Inference

Filters

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(z $\ge$ -0.9)

Let z be a random variable with a standard normal distribution. Find the indicated probability below. P(-1.7 $\le$ z $\le$ -0.8)

Assume that x has a normal distribution, with the specified mean and standard deviation. Find the indicated probabilities. P(1 $\le$ x $\le$ 18) $\mu$ = 12; $\sigma$ = 4

The heights of 18-year-old men are approximately normally distributed with mean 68 inches and standard deviation 3 inches. What is the probability that the average height of a sample of ten 18-year-old men will be between 67 and 68 inches? $\bar { x }$