Question 1

A 95% confidence interval with df = 29

Accepted Answer

A) 2.042 
B) 2.462 
C) 2.048 
D) 1.960 
E) 2.045 
A) 2.042 
B) 2.462 
C) 2.048 
D) 1.960 
E) 2.045

Question 2

A manufacturer claims that the mean amount of juice in its 473 mL bottles is 476 mL.A consumer advocacy group wants to perform a hypothesis test to determine whether the mean amount is actually less than this.The hypotheses are:  
: μ = 476 mL  
: μ < 476 mL
Explain the result of a Type I error.

Accepted Answer

A) The advocacy group will conclude that the mean amount of juice is 476 mL when in fact it is 476 mL. 
B) The advocacy group will conclude that the mean amount of juice is greater than 476 mL when in fact it is 476 mL. 
C) The advocacy group will conclude that the mean amount of juice is less than 476 mL when in fact it is 476 mL. 
D) The advocacy group will conclude that the mean amount of juice is less than 476 mL when in fact it is less than 476 mL. 
E) The advocacy group will conclude that the mean amount of juice is 476 mL when in fact it is less than 476 mL. 
A) The advocacy group will conclude that the mean amount of juice is 476 mL when in fact it is 476 mL. 
B) The advocacy group will conclude that the mean amount of juice is greater than 476 mL when in fact it is 476 mL. 
C) The advocacy group will conclude that the mean amount of juice is less than 476 mL when in fact it is 476 mL. 
D) The advocacy group will conclude that the mean amount of juice is less than 476 mL when in fact it is less than 476 mL. 
E) The advocacy group will conclude that the mean amount of juice is 476 mL when in fact it is less than 476 mL.

Question 3

A random sample of 30 households was selected from a particular neighborhood.The number of cars for each household is shown below.Estimate the mean number of cars per household for the population of households in this neighborhood.Give the 95% confidence interval.

Accepted Answer

A) (1.5,2) 
B) (1,2) 
C) (1.5,1.7) 
D) (1.3,1.7) 
E) (0.9,2.1) 
A) (1.5,2) 
B) (1,2) 
C) (1.5,1.7) 
D) (1.3,1.7) 
E) (0.9,2.1)

Question 4

At one school,the average amount of time that tenth-graders spend watching television each week is 21.6 hours.The principal introduces a campaign to encourage the students to watch less television.One year later,the principal wants to perform a hypothesis test to determine whether the average amount of time spent watching television per week has decreased from the previous mean of 21.6 hours.

Accepted Answer

A) Upper-tailed 
B) Two-sided 
C) Lower-tailed 
A) Upper-tailed 
B) Two-sided 
C) Lower-tailed

Question 5

A sample of 51 statistics students at a large university had a mean final exam score of 76 with a standard deviation of 4.Find a 95% confidence interval for the mean final exam score for all statistics students at this university.

Accepted Answer

A) (75.6,76.1) 
B) (75.6,76.4) 
C) (79.4,82.6) 
D) (74.9,77.1) 
E) (75.9,76.1) 
A) (75.6,76.1) 
B) (75.6,76.4) 
C) (79.4,82.6) 
D) (74.9,77.1) 
E) (75.9,76.1)

Question 6

How tall is your average statistics classmate? To determine this,you measure the height of a random sample of 15 of your 200 fellow students,finding a mean height of 166.6 cm and a standard deviation of 5.64 cm.Construct a 90% confidence interval for the mean height of your classmates.

Accepted Answer

A) (163.73,169.27) 
B) (164.04,169.16) 
C) (165.992,167.01) 
D) (164.02,168.98) 
E) (164.91,1 70.09) 
A) (163.73,169.27) 
B) (164.04,169.16) 
C) (165.992,167.01) 
D) (164.02,168.98) 
E) (164.91,1 70.09)

A 95% confidence interval with df = 29

A manufacturer claims that the mean amount of juice in its 473 mL bottles is 476 mL.A consumer advocacy group wants to perform a hypothesis test to determine whether the mean amount is actually less than this.The hypotheses are: : μ = 476 mL : μ < 476 mL Explain the result of a Type I error.

A random sample of 30 households was selected from a particular neighborhood.The number of cars for each household is shown below.Estimate the mean number of cars per household for the population of households in this neighborhood.Give the 95% confidence interval.

A sample of 51 statistics students at a large university had a mean final exam score of 76 with a standard deviation of 4.Find a 95% confidence interval for the mean final exam score for all statistics students at this university.

How tall is your average statistics classmate? To determine this,you measure the height of a random sample of 15 of your 200 fellow students,finding a mean height of 166.6 cm and a standard deviation of 5.64 cm.Construct a 90% confidence interval for the mean height of your classmates.

Data

Displaying and Describing Categorical Data

Displaying and Summarizing Quantitative Data

Understanding and Comparing Distributions

The Standard Deviation As a Ruler and the Normal Model

Scatterplots, association, and Correlation

Linear Regression

Regression Wisdom

Re-Expressing Data: Get It Straight

Understanding Randomness

Sample Surveys

Experiments and Observational Surveys

From Randomness to Probability

Probability Rules

Random Variables

Probability Models

Sampling Distribution Models

Confidence Intervals for Proportions

Testing Hypotheses About Proportions

More About Tests

Comparing Two Proportions

Comparing Means

Paired Samples and Blocks

Comparing Counts

Inferences for Regression

Analysis of Variance

Multifactor Analysis of Variance

Multiple Regression

Multiple Regression Wisdom

Rank-Based Nonparametric Tests

The Bootstrap

Filters

Exam 22: Inferences About Means

A 95% confidence interval with df = 29

A manufacturer claims that the mean amount of juice in its 473 mL bottles is 476 mL.A consumer advocacy group wants to perform a hypothesis test to determine whether the mean amount is actually less than this.The hypotheses are: : μ = 476 mL : μ < 476 mL Explain the result of a Type I error.

A random sample of 30 households was selected from a particular neighborhood.The number of cars for each household is shown below.Estimate the mean number of cars per household for the population of households in this neighborhood.Give the 95% confidence interval.

A sample of 51 statistics students at a large university had a mean final exam score of 76 with a standard deviation of 4.Find a 95% confidence interval for the mean final exam score for all statistics students at this university.

How tall is your average statistics classmate? To determine this,you measure the height of a random sample of 15 of your 200 fellow students,finding a mean height of 166.6 cm and a standard deviation of 5.64 cm.Construct a 90% confidence interval for the mean height of your classmates.

Data

Displaying and Describing Categorical Data

Displaying and Summarizing Quantitative Data

Understanding and Comparing Distributions

The Standard Deviation As a Ruler and the Normal Model

Scatterplots, association, and Correlation

Linear Regression

Regression Wisdom

Re-Expressing Data: Get It Straight

Understanding Randomness

Sample Surveys

Experiments and Observational Surveys

From Randomness to Probability

Probability Rules

Random Variables

Probability Models

Sampling Distribution Models

Confidence Intervals for Proportions

Testing Hypotheses About Proportions

More About Tests

Comparing Two Proportions

Comparing Means

Paired Samples and Blocks

Comparing Counts

Inferences for Regression

Analysis of Variance

Multifactor Analysis of Variance

Multiple Regression

Multiple Regression Wisdom

Rank-Based Nonparametric Tests

The Bootstrap

Filters