Question 1

A point estimate is a range of values used to estimate a population parameter.

Accepted Answer

A) True 
 B)False

Question 2

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. Assuming a population standard deviation of 6 hours, what is the required sample size if the error should be less than ½ hour with a 95% level of confidence?

Accepted Answer

A)  554 
B)  130 
C)  35 
D)  393 
A)  554 
B)  130 
C)  35 
D)  393

Question 3

A group of statistics students decided to conduct a survey at their university to find the average (mean) amount of time students spent studying per week. They sampled 240 students and found a mean of 22.3 hours per week. Assuming a population standard deviation of 6 hours, what is the 99% level of confidence?

Accepted Answer

A)  [21.80, 22.80] 
B)  [16.3, 28.3] 
C)  [21.30, 23.30] 
D)  [20.22, 22.0] 
A)  [21.80, 22.80] 
B)  [16.3, 28.3] 
C)  [21.30, 23.30] 
D)  [20.22, 22.0]

Question 4

A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98 with a standard error of $0.10. What is the 98% confidence interval to estimate the true cost of a gallon of milk?

Accepted Answer

A)  $2.73 to $3.23 
B)  $2.85 to $3.11 
C)  $2.94 to $3.02 
D)  $2.95 to $3.01 
A)  $2.73 to $3.23 
B)  $2.85 to $3.11 
C)  $2.94 to $3.02 
D)  $2.95 to $3.01

Question 5

For a sampling distribution of the means, what percent of the means would be between  $\pm$ 1.96 standard deviations? ______________

Accepted Answer

The answer of For a sampling distribution of the means,...

Question 6

Which of the following would be used as a point estimate for the population mean ( µ )?

Accepted Answer

A) $\sigma$ 
B)    
C)    
D)  s 
A) $\sigma$ 
B)    
C)    
D)  s

Question 7

A sample of 50 is selected from a known population of 250 elements. The population standard deviation is 15. Using the finite correction factor, what is the standard error of the sample means?

Accepted Answer

A)  2.89 
B)  1.90 
C)  2.12 
D)  Cannot be determined 
A)  2.89 
B)  1.90 
C)  2.12 
D)  Cannot be determined

Question 8

In order to construct the 68 percent confidence interval, how many standard errors of the mean from the hypothesized population mean must you go? __________

Accepted Answer

1, or plus

Question 9

Sugar is packaged in 16 ounce bags. If 42 bags are sampled, with a mean of 15.95 ounces and a standard deviation of 0.4 ounces, what is the 99 percent confidence interval estimate of the population mean?

Accepted Answer

The answer of Sugar is packaged in 16 ounce bags....

Question 10

A random sample of 85 group leaders and supervisors revealed that they worked an average of 6.5 years before being promoted. The population standard deviation was 1.7 years. Using the 0.95 degree of confidence, what is the confidence interval for the population mean?

Accepted Answer

A)  6.99 and 7.99 
B)  4.15 and 7.15 
C)  6.14 and 6.86 
D)  6.49 and 7.49 
A)  6.99 and 7.99 
B)  4.15 and 7.15 
C)  6.14 and 6.86 
D)  6.49 and 7.49

Question 11

A survey of 16 executives showed a mean work time per week of 50 hours, with a standard deviation of 10 hours. What is the 95 percent confidence interval for the population mean?

Accepted Answer

The answer of A survey of 16 executives showed a...

Question 12

A local grocery store wants to estimate the mean daily number of gallons of milk sold to customers. Assume the number of gallons sold follows the normal distribution with a population standard deviation of 5.10 gallons. A random sample of 60 days shows that the mean daily number of gallons sold is 10.00. What is the point estimate of the population mean?

Accepted Answer

The answer of A local grocery store wants to estimate...

Question 13

A company's headquarters is located in downtown Chicago. The company is interested to know the mean driving time of its employees if they require their employees to start working at 6:00 am. Fifty employees are randomly sampled over four weeks and asked to record their driving time. The mean driving time is 35 minutes with a standard deviation is 10 minutes.
What is the 98 percent confidence interval for the population mean?

Accepted Answer

The answer of A company's headquarters is located in downtown...

Question 14

There are 2,000 eligible voters in a precinct. 500 of the voters are randomly selected and asked whether they planned to vote for the Democratic incumbent or the Republican challenger. Of the 500 surveyed, 350 said they would vote for the Democratic incumbent. Using the 0.99 confidence coefficient, what are the confidence limits for the proportion that plan to vote for the Democratic incumbent?

Accepted Answer

A)  0.647 and 0.753 
B)  0.612 and 0.712 
C)  0.397 and 0.797 
D)  0.826 and 0.926 
A)  0.647 and 0.753 
B)  0.612 and 0.712 
C)  0.397 and 0.797 
D)  0.826 and 0.926

Question 15

A finite population correction factor is used when we know the _________________.

Accepted Answer

The answer of A finite population correction factor is used...

Question 16

What does the t distribution approach as the sample size increases? ______________________

Accepted Answer

Standard n

Question 17

If university officials say that at least 70% of the voting student population supporting the fee increase, if the 95% confidence interval is [0.75, 0.85], what conclusion can be drawn based on a 95% level of confidence?

Accepted Answer

A)  70% is not in the interval, need to take another sample 
B)  70% is not in the interval, so assume it will not be supported 
C)  70% is below the interval, so assume it will be supported 
D)  Since this was not based on population, cannot make conclusion 
A)  70% is not in the interval, need to take another sample 
B)  70% is not in the interval, so assume it will not be supported 
C)  70% is below the interval, so assume it will be supported 
D)  Since this was not based on population, cannot make conclusion

Question 18

A sample of 500 students is selected from a known population of 15000 students to construct a 99% confidence interval for the average SAT score. What correction factor should be used to compute the standard error?

Accepted Answer

A)  0.9499 
B)  0.9832 
C)  2.5760 
D)  Cannot be determined 
A)  0.9499 
B)  0.9832 
C)  2.5760 
D)  Cannot be determined

Question 19

A sample of 25 is selected from a known population of 100 elements. What is the finite population correction factor?

Accepted Answer

A)  8.66 
B)  75 
C)  0.87 
D)  Cannot be determined 
A)  8.66 
B)  75 
C)  0.87 
D)  Cannot be determined

Question 20

When a confidence interval for a population mean is constructed from sample data,

Accepted Answer

A)  we can conclude that the population mean is in the interval 
B)  we can conclude that the population mean is not in the interval 
C)  we can conclude, for an infinite number of samples and corresponding confidence intervals, that the population mean is in a stated percentage of the intervals 
D)  we cannot make any inferences 
A)  we can conclude that the population mean is in the interval 
B)  we can conclude that the population mean is not in the interval 
C)  we can conclude, for an infinite number of samples and corresponding confidence intervals, that the population mean is in a stated percentage of the intervals 
D)  we cannot make any inferences

A point estimate is a range of values used to estimate a population parameter.

A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98 with a standard error of $0.10. What is the 98% confidence interval to estimate the true cost of a gallon of milk?

For a sampling distribution of the means, what percent of the means would be between $\pm$ 1.96 standard deviations? ______________

Which of the following would be used as a point estimate for the population mean ( µ )?

A sample of 50 is selected from a known population of 250 elements. The population standard deviation is 15. Using the finite correction factor, what is the standard error of the sample means?

In order to construct the 68 percent confidence interval, how many standard errors of the mean from the hypothesized population mean must you go? __________

Sugar is packaged in 16 ounce bags. If 42 bags are sampled, with a mean of 15.95 ounces and a standard deviation of 0.4 ounces, what is the 99 percent confidence interval estimate of the population mean?

A random sample of 85 group leaders and supervisors revealed that they worked an average of 6.5 years before being promoted. The population standard deviation was 1.7 years. Using the 0.95 degree of confidence, what is the confidence interval for the population mean?

A survey of 16 executives showed a mean work time per week of 50 hours, with a standard deviation of 10 hours. What is the 95 percent confidence interval for the population mean?

A finite population correction factor is used when we know the _________________.

What does the t distribution approach as the sample size increases? ______________________

If university officials say that at least 70% of the voting student population supporting the fee increase, if the 95% confidence interval is [0.75, 0.85], what conclusion can be drawn based on a 95% level of confidence?

A sample of 500 students is selected from a known population of 15000 students to construct a 99% confidence interval for the average SAT score. What correction factor should be used to compute the standard error?

A sample of 25 is selected from a known population of 100 elements. What is the finite population correction factor?

When a confidence interval for a population mean is constructed from sample data,

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Methods and the Central Limit Theorem

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Index Numbers

Time Series and Forecasting

Nonparametric Methods: Goodness-Of-Fit Tests

Nonparametric Methods: Analysis of Ranked Data

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

Exam 9: Estimation and Confidence Intervals

A point estimate is a range of values used to estimate a population parameter.

A survey of 25 grocery stores revealed that the average price of a gallon of milk was $2.98 with a standard error of $0.10. What is the 98% confidence interval to estimate the true cost of a gallon of milk?

For a sampling distribution of the means, what percent of the means would be between ±\pm± 1.96 standard deviations? ______________

Which of the following would be used as a point estimate for the population mean ( µ )?

A sample of 50 is selected from a known population of 250 elements. The population standard deviation is 15. Using the finite correction factor, what is the standard error of the sample means?

In order to construct the 68 percent confidence interval, how many standard errors of the mean from the hypothesized population mean must you go? __________

Sugar is packaged in 16 ounce bags. If 42 bags are sampled, with a mean of 15.95 ounces and a standard deviation of 0.4 ounces, what is the 99 percent confidence interval estimate of the population mean?

A random sample of 85 group leaders and supervisors revealed that they worked an average of 6.5 years before being promoted. The population standard deviation was 1.7 years. Using the 0.95 degree of confidence, what is the confidence interval for the population mean?

A survey of 16 executives showed a mean work time per week of 50 hours, with a standard deviation of 10 hours. What is the 95 percent confidence interval for the population mean?

A finite population correction factor is used when we know the _________________.

What does the t distribution approach as the sample size increases? ______________________

If university officials say that at least 70% of the voting student population supporting the fee increase, if the 95% confidence interval is [0.75, 0.85], what conclusion can be drawn based on a 95% level of confidence?

A sample of 500 students is selected from a known population of 15000 students to construct a 99% confidence interval for the average SAT score. What correction factor should be used to compute the standard error?

A sample of 25 is selected from a known population of 100 elements. What is the finite population correction factor?

When a confidence interval for a population mean is constructed from sample data,

What Is Statistics

Describing Data: Frequency Tables, Frequency Distributions, and Graphic Presentation

Describing Data: Numerical Measures

Describing Data: Displaying and Exploring Data

A Survey of Probability Concepts

Discrete Probability Distributions

Continuous Probability Distributions

Sampling Methods and the Central Limit Theorem

One-Sample Tests of Hypothesis

Two-Sample Tests of Hypothesis

Analysis of Variance

Correlation and Linear Regression

Multiple Regression Analysis

Index Numbers

Time Series and Forecasting

Nonparametric Methods: Goodness-Of-Fit Tests

Nonparametric Methods: Analysis of Ranked Data

Statistical Process Control and Quality Management

An Introduction to Decision Theory

Filters

For a sampling distribution of the means, what percent of the means would be between $\pm$ 1.96 standard deviations? ______________