Question 1

When the expected​ value of the point estimator is equal to the population parameter it estimates, it is said to be ​

Accepted Answer

A) ​unbiased. 
B) ​precise. 
C) symmetric. 
D) predicted. 
A) ​unbiased. 
B) ​precise. 
C) symmetric. 
D) predicted. A

Question 2

For a population with an unknown distribution, the form of the sampling distribution of the sample mean is

Accepted Answer

A) approximately normal for small sample sizes. 
B) exactly normal for large sample sizes. 
C) exactly normal for small sample sizes. 
D) approximately normal for large sample sizes. 
A) approximately normal for small sample sizes. 
B) exactly normal for large sample sizes. 
C) exactly normal for small sample sizes. 
D) approximately normal for large sample sizes. D

Question 3

A sample of 37 AA batteries had a mean lifetime of 584 hours. A 95% confidence interval for the population mean was 579.2 < μ < 588.8. Which statements is the correct interpretation of the results?

Accepted Answer

A) We are 95% confident that the mean lifetime of all the bulbs in the population is between 579.2 hours and 588.8 hours. 
B) The probability that the population mean is between 579.2 hours and 588.8 hours is 0.95. 
C) 95% of the light bulbs in the sample had lifetimes between 579.2 hours and 588.8 hours. 
D) None of these statements correctly interpret the results. 
A) We are 95% confident that the mean lifetime of all the bulbs in the population is between 579.2 hours and 588.8 hours. 
B) The probability that the population mean is between 579.2 hours and 588.8 hours is 0.95. 
C) 95% of the light bulbs in the sample had lifetimes between 579.2 hours and 588.8 hours. 
D) None of these statements correctly interpret the results. A

Question 4

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution when
​

Accepted Answer

n(1 - p) 5

Question 5

A large manufacturing plant has analyzed the amount of time required to produce an electrical part and determined that the times follow a normal distribution with mean time ? = 45 hours. The production manager has developed a new procedure for producing the part. He believes that the new procedure will decrease the population mean amount of time required to produce the part. After training a group of production line workers, a random sample of 25 parts will be selected and the average amount of time required to produce them will be determined. If the switch is made to the new procedure, the cost to implement the new procedure will be more than offset by the savings in manpower required to produce the parts. Use the hypotheses: Ho: ? ? .45 hours and Ha: ? < 45 hours. Determine the p-value of the test statistic if the sample mean amount of time is $\bar { x }$ = 43.118 hours with the sample standard deviation s = 5.5 hours.

Accepted Answer

A) ?0.04973 
B) 0.04999 
C) ?0.95818 
D) 0.04354 
A) ?0.04973 
B) 0.04999 
C) ?0.95818 
D) 0.04354

Question 6

Sample statistics, such as , s, or , that provide an estimate of the population parameter are known as
​

Accepted Answer

The answer of Sample statistics, such as , s, or...

Question 7

The CEO of a company wants to estimate the percent of employees that use company computers to go on Facebook during work hours with 95% confidence. He selects a random sample of 150 of the employees and finds that 53 of them logged onto Facebook that day. What is the estimate of the standard error of the proportion $\sigma _ { \bar { p } } ?$

Accepted Answer

A) 0.039 
B) 0.050 
C) 0.350 
D) 0.455 
A) 0.039 
B) 0.050 
C) 0.350 
D) 0.455

Question 8

A student wants to determine if pennies are really fair, meaning equally likely to land heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads up. What are the appropriate null and alternative hypotheses?

Accepted Answer

A) H0: p ≥ 0.5, Ha : p  
B) H0: p ≤ 0.5, Ha : p ≠ 0.5 
C) ​H0: p = 0.5, Ha : p > 0.5 
D) H0: p ≥ 28, Ha : p  
A) H0: p ≥ 0.5, Ha : p  
B) H0: p ≤ 0.5, Ha : p ≠ 0.5 
C) ​H0: p = 0.5, Ha : p > 0.5 
D) H0: p ≥ 28, Ha : p

Question 9

A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size

Accepted Answer

A) N and n have the same probability of being selected. 
B) n has a probability of 0.5 of being selected. 
C) n has a probability of 0.05 of being selected. 
D) n has the same probability of being selected. 
A) N and n have the same probability of being selected. 
B) n has a probability of 0.5 of being selected. 
C) n has a probability of 0.05 of being selected. 
D) n has the same probability of being selected.

Question 10

A statistics teacher started class one day by drawing the names of 10 students out of a hat and asked them to do as many pushups as they could. The 10 randomly selected students averaged 15 pushups per person with a standard deviation of 9 pushups.Suppose the distribution of the population of number of pushups that can be done is approximately normal. What is the standard error of the mean?

Accepted Answer

A) ​0.900 
B) ​2.876 
C) ​3.061 
D) 4.743 
A) ​0.900 
B) ​2.876 
C) ​3.061 
D) 4.743

Question 11

A simple random sample of 31 observations was taken from a large population. The sample mean equals 5. Five is a ​

Accepted Answer

A) ​population parameter. 
B) ​point estimate. 
C) ​population mean. 
D) ​standard error. 
A) ​population parameter. 
B) ​point estimate. 
C) ​population mean. 
D) ​standard error.

Question 12

Which statement is NOT true? ​​

Accepted Answer

A) The greater the level of confidence, the more likely it is that the confidence interval actually includes the true population mean. 
B) The greater the level of confidence, the larger the z-score. 
C) The greater the level of confidence, the wider the confidence interval. 
D) Rejecting the null hypothesis when it is true is a Type II error. 
A) The greater the level of confidence, the more likely it is that the confidence interval actually includes the true population mean. 
B) The greater the level of confidence, the larger the z-score. 
C) The greater the level of confidence, the wider the confidence interval. 
D) Rejecting the null hypothesis when it is true is a Type II error.

Question 13

Which statement is NOT true? ​​

Accepted Answer

A) Rejecting the null hypothesis when it is true is a Type I error. 
B) The probability of making a Type I error is symbolized by α. 
C) Failing to reject the null hypothesis when it is false is a Type I error. 
D) Type II error can occur for both one and two-tailed tests. 
A) Rejecting the null hypothesis when it is true is a Type I error. 
B) The probability of making a Type I error is symbolized by α. 
C) Failing to reject the null hypothesis when it is false is a Type I error. 
D) Type II error can occur for both one and two-tailed tests.

Question 14

Using an α = 0.04 a confidence interval for a population proportion is determined to be 0.65 to 0.75. If the level of significance is decreased, the interval for the population proportion ​

Accepted Answer

A) ​becomes narrower. 
B) ​becomes wider. 
C) ​does not change. 
D) remains the same. 
A) ​becomes narrower. 
B) ​becomes wider. 
C) ​does not change. 
D) remains the same.

Question 15

A random sample of 150 people was taken from a very large population. Ninety of the people in the sample were female. What is the standard error of the proportion?
​

Accepted Answer

The answer of A random sample of 150 people was...

Question 16

A random sample selected from an infinite population is a sample selected such that each element selected comes from the same ________________ and each element is selected ______________

Accepted Answer

A) ​population; independently. 
B) ​population; simultaneously. 
C) ​sample; independently. 
D) sample; simultaneously. 
A) ​population; independently. 
B) ​population; simultaneously. 
C) ​sample; independently. 
D) sample; simultaneously.

Question 17

In a survey of 3539 female university students ages​ 18-22, 401 say they live in off-campus housing. If you constructed 90% and 95% confidence intervals for the population proportion how would they differ? As the level of confidence ________________, the confidence interval gets ___________________.
​

Accepted Answer

increases; wider. Al

Question 18

Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed: Ho: μ = 11 Ha: μ > 11

Accepted Answer

A) ​left-tailed. 
B) right-tailed. 
C) ​two-tailed. 
D) there is not enough information to make a determination. 
A) ​left-tailed. 
B) right-tailed. 
C) ​two-tailed. 
D) there is not enough information to make a determination.

Question 19

The t value for a 99% confidence interval estimation based upon a sample of size 10 is

Accepted Answer

A) ​1.645. 
B) ​1.812. 
C) ​2.576. 
D) 3.169. 
A) ​1.645. 
B) ​1.812. 
C) ​2.576. 
D) 3.169.

Question 20

As the sample size increases, the standard error of the mean ______________.
​

Accepted Answer

The answer of As the sample size increases, the standard...

When the expected value of the point estimator is equal to the population parameter it estimates, it is said to be

For a population with an unknown distribution, the form of the sampling distribution of the sample mean is

A sample of 37 AA batteries had a mean lifetime of 584 hours. A 95% confidence interval for the population mean was 579.2 < μ < 588.8. Which statements is the correct interpretation of the results?

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution when

Sample statistics, such as , s, or , that provide an estimate of the population parameter are known as

A student wants to determine if pennies are really fair, meaning equally likely to land heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads up. What are the appropriate null and alternative hypotheses?

A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size

A simple random sample of 31 observations was taken from a large population. The sample mean equals 5. Five is a

Which statement is NOT true?

Which statement is NOT true?

Using an α = 0.04 a confidence interval for a population proportion is determined to be 0.65 to 0.75. If the level of significance is decreased, the interval for the population proportion

A random sample of 150 people was taken from a very large population. Ninety of the people in the sample were female. What is the standard error of the proportion?

A random sample selected from an infinite population is a sample selected such that each element selected comes from the same __ and each element is selected

In a survey of 3539 female university students ages 18-22, 401 say they live in off-campus housing. If you constructed 90% and 95% confidence intervals for the population proportion how would they differ? As the level of confidence , the confidence interval gets ___.

Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed: H_o: μ = 11 H_a: μ > 11

The t value for a 99% confidence interval estimation based upon a sample of size 10 is

As the sample size increases, the standard error of the mean ______________.

Introduction

Descriptive Statistics

Data Visualization

Descriptive Data Mining

Probability: an Introduction to Modeling Uncertainty

Linear Regression

Time Series Analysis and Forecasting

Predictive Data Mining

Spreadsheet Models

Linear Optimization Models

Integer Linear Optimization Models

Nonlinear Optimization Models

Monte Carlo Simulation

Decision Analysis

Filters

Exam 6: Statistical Inference

When the expected​ value of the point estimator is equal to the population parameter it estimates, it is said to be ​

For a population with an unknown distribution, the form of the sampling distribution of the sample mean is

A sample of 37 AA batteries had a mean lifetime of 584 hours. A 95% confidence interval for the population mean was 579.2 < μ < 588.8. Which statements is the correct interpretation of the results?

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution when ​

Sample statistics, such as , s, or , that provide an estimate of the population parameter are known as ​

A student wants to determine if pennies are really fair, meaning equally likely to land heads up or tails up. He flips a random sample of 50 pennies and finds that 28 of them land heads up. What are the appropriate null and alternative hypotheses?

A simple random sample of size n from a finite population of size N is a sample selected such that each possible sample of size

A simple random sample of 31 observations was taken from a large population. The sample mean equals 5. Five is a ​

Which statement is NOT true? ​​

Which statement is NOT true? ​​

Using an α = 0.04 a confidence interval for a population proportion is determined to be 0.65 to 0.75. If the level of significance is decreased, the interval for the population proportion ​

A random sample of 150 people was taken from a very large population. Ninety of the people in the sample were female. What is the standard error of the proportion? ​

A random sample selected from an infinite population is a sample selected such that each element selected comes from the same ________________ and each element is selected ______________

Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed: Ho: μ = 11 Ha: μ > 11

The t value for a 99% confidence interval estimation based upon a sample of size 10 is

As the sample size increases, the standard error of the mean ______________. ​

Introduction

Descriptive Statistics

Data Visualization

Descriptive Data Mining

Probability: an Introduction to Modeling Uncertainty

Linear Regression

Time Series Analysis and Forecasting

Predictive Data Mining

Spreadsheet Models

Linear Optimization Models

Integer Linear Optimization Models

Nonlinear Optimization Models

Monte Carlo Simulation

Decision Analysis

Filters

When the expected value of the point estimator is equal to the population parameter it estimates, it is said to be

As a rule of thumb, the sampling distribution of the sample proportions can be approximated by a normal probability distribution when

Sample statistics, such as , s, or , that provide an estimate of the population parameter are known as

A simple random sample of 31 observations was taken from a large population. The sample mean equals 5. Five is a

Which statement is NOT true?

Which statement is NOT true?

Using an α = 0.04 a confidence interval for a population proportion is determined to be 0.65 to 0.75. If the level of significance is decreased, the interval for the population proportion

A random sample of 150 people was taken from a very large population. Ninety of the people in the sample were female. What is the standard error of the proportion?

A random sample selected from an infinite population is a sample selected such that each element selected comes from the same __ and each element is selected

Determine whether the alternative hypothesis is left-tailed, right-tailed, or two-tailed: H_o: μ = 11 H_a: μ > 11

As the sample size increases, the standard error of the mean ______________.