Question 1 of 36

A sample of size will be drawn from a population with mean and standard deviation . Use the

Cumulative Normal Distribution Table if needed.

(a) Find the probability that will be less than . Round the final answer to at least four decimal

places.

(b) Find the percentile of . Round the answer to at least two decimal places.

Part 1 of 2

Find the probability that will be less than . Round the final answer to at least four decimal

places.

Find the percentile of . Round the answer to at least two decimal places.

Question 2 of 36

A sample of size will be drawn from a population with mean and standard deviation . Use the

Cumulative Normal Distribution Table if needed.

(a) Find the probability that will be less than . Round the final answer to at least four decimal

places.

(b) Find the percentile of . Round the answer to at least two decimal places.

80 81 22

x 86

85th x

x 86

The probability that x will be less than 86 is .

85th x

The 85th percentile of x is .

50 72 20

x 73

55th x

Find the probability that will be less than . Round the final answer to at least four decimal

places.

Part 2 of 2

Find the percentile of . Round the answer to at least two decimal places.

Question 3 of 36

A sample of size will be drawn from a population with mean and standard deviation . Use the

Cumulative Normal Distribution Table if needed.

(a) Find the probability that will be between and . Round the final answer to at least four

decimal places.

(b) Find the percentile of . Round the answer to at least two decimal places.

Part 1 of 2

Find the probability that will be between and . Round the final answer to at least four

decimal places.

Part 2 of 2

Find the percentile of . Round the answer to at least two decimal places.

x 73

The probability that x will be less than 73 is .

55th x

The 55th percentile of x is .

105 15 6

x 14 16

55th x

x 14 16

The probability that x will be between 14 and 16 is .

55th x

The 55th percentile of x is .

Question 4 of 36

Watch your cholesterol: The mean serum cholesterol level for U.S. adults was , with a standard

deviation of (the units are milligrams per deciliter). A simple random sample of adults is chosen.

Use the Cumulative Normal Distribution Table if needed. Round the answers to at least four decimal

places.

(a) What is the probability that the sample mean cholesterol level is greater than ?

(b) What is the probability that the sample mean cholesterol level is between and ?

(c) Would it be unusual for the sample mean to be less than ?

Part 1 of 3

What is the probability that the sample mean cholesterol level is greater than ?

Part 2 of 3

What is the probability that the sample mean cholesterol level is between and ?

Part 3 of 3

Would it be unusual for the sample mean to be less than ?

202

41 110

210

190 200

198

210

The probability that the sample mean cholesterol level is greater than 210 is .

190 200

The probability that the sample mean cholesterol level is between 190 and 200 is .

198

It be unusual for the sample mean to be less than , since the probability is

.

(Choose one) ▼ 198

Question 5 of 36

Taxes: The Internal Revenue Service reports that the mean federal income tax paid in the year

was . Assume that the standard deviation is . The IRS plans to draw a sample of tax

returns to study the effect of a new tax law.

(a) What is the probability that the sample mean tax is less than ?

(b) What is the probability that the sample mean tax is between and ?

(c) Find the percentile of the sample mean.

(d) Would it be unusual if the sample mean were less than ?

(e) Do you think it would be unusual for an individual to pay a tax of less than ? Explain.

Part 1 of 5

(a) What is the probability that the sample mean tax is less than ? Round the answer to at

least four decimal places.

Part 2 of 5

(b) What is the probability that the sample mean tax is between and ? Round the

answer to at least four decimal places.

Part 3 of 5

(c) Find the percentile of the sample mean. Round the answer to at least one decimal place.

2010

$8040 $4700 1000

$8100

$7600 $8000

10th

$7600

$7600

$8100

The probability that the sample mean tax is less than $8100 is .

$7600 $8000

The probability that the sample mean tax is between $7600 and $8000 is .

10th

The 10th percentile of the sample mean is $ .

Part 4 of 5

(d) Would it be unusual if the sample mean were less than ? Round the answer to at least

four decimal places.

Part 5 of 5

(e) Do you think it would be unusual for an individual to pay a tax of less than ? Explain.

Assume the population is approximately normal. Round the answer to at least four decimal places.

Question 6 of 36

High-rent district: The mean monthly rent for a one-bedroom apartment without a doorman in

Manhattan is . Assume the standard deviation is . A real estate firm samples apartments.

Use the Cumulative Normal Distribution Table if needed.

(a) What is the probability that the sample mean rent is greater than ?

(b) What is the probability that the sample mean rent is between and ?

(c) Find the percentile of the sample mean.

(d) Would it be unusual if the sample mean were greater than ?

(e) Do you think it would be unusual for an individual apartment to have a rent greater than ?

Explain. Assume the population is approximately normal.

Part 1 of 5

(a) What is the probability that the sample mean rent is greater than ? Round the answer to

at least four decimal places.

$7600

It unusual because the probability of the sample mean being less than is

.

(Choose one) ▼ $7600

$7600

It be unusual for an individual to pay a tax of less than , since the

probability is .

(Choose one) ▼ $7600

$2550 $485 85

$2620

$2419 $2519

60th

$2700

$2700

$2620

The probability that the sample mean rent is greater than $2620