discussion board 12

Post ID: 3209439

Overview

Discussion Board 12 – CI & Hyp– 2 IND Populations and Matched Pairs - Hypothesis Testing

1. You would like to construct a 95% confidence interval to see the mean difference in the amount of time spent studying for Freshman and Sophomores. Use the following information: © Chris O’Byrne 2024

FRESHMANSOPHOMORES

9.7Sample Mean (hours)8.25

3.3Population Standard Deviation3.3

40Sample Size45

A. Construct a 95% confidence interval for the mean difference in the amount of time spent studying for Freshman and Sophomores. (round margin of error to 3 decimal places at the end) and (express the final answer in such fashion ex. 1.234 to 2.567)

B. What is the Confidence value you used (z or t value used)?

C. What is the Margin of error (rounded to 4 decimal places)?

D. What is the Standard Error (rounded to 4 decimal places)?

2. You would like to construct a hypothesis test to see if there is a difference in units taken per semester for Juniors and Seniors. Use the following information: © Chris O’Byrne 2024

JUNIORSENIOR

14.25Mean Units Taken13.45

4.3Population Variance4.3

60Sample Size55

A. What is the value of the test statistic (correct number of decimal places depending on which test statistic)?

B. What is the probability of the test statistic for this specific problem (p-value)? (take into consideration if this is 1-tail or 2-tail test)

C. What conclusion will you come to? (just need to state Accept Ho or Reject Ho and Accept Ha – just put one of those 2 answers in the body of the discussion board, but you will have a more detailed solution on your worksheet that you will attach as a PDF). Use a level of significance of .05.

3. You would like to conduct a hypothesis test to see if there is a difference in the cost of store items between Michael’s and JoAnne’s. We have randomly selected 12 store items from Michael’s and JoAnne’s to see if there is a difference in the cost of these items. Use the following information:

Purchases

Michael’s

JoAnne’s

Difference

$ 17.50

$ 15.50

$ 2.00

$ 24.50

$ 25.00

$ (.50)

…

$ 9.50

$ 10.50

$ (1.00)

$ 13.00

$ 9.50

$ 3.50

$ 265.00

Total

$ 229.00

$ 36.00

Total Difference

$ 4.05

Standard Deviation

of the Differences

A. What is the test statistics value (correct number of decimal places depending on which test statistic)?

B. What is the probability of the test statistic for this specific problem? (take into consideration if this is 1-tail or 2-tail test)

C. What conclusion will you come to? (just need to state Accept Ho or Reject Ho and Accept Ha – just put one of those 2 answers in the body of the discussion board, but you will have a more detailed solution (besides writing one of these statements you will write out in words what the conclusion means) on your worksheet that you will attach as a PDF). Use a level of significance of .05.

D. Using the critical value approach at what critical value or values will you start rejecting the null hypothesis? (make sure you are very careful and detailed with your answer, pay attention to signs and values)