Question

Alessandra DiMauro Do male and female servers work the same number of hours? A sample of 22 female servers worked an average of 37 hours per week, with a standard deviation of 3. A sample of 19 male servers worked an average of 27 hours per week, with a standard deviation of 4. Let and ?2 represent the typical number of hours worked by all female and male servers, respectively. Construct a 80% confidence interval for ?1-?2. Enter your answer as an equation or as a number rounded to three decimal places and round all interim calculations to three decimal places. Lower bound on Cl 8.596 Upper bound on CI-11.404 Which of the following does your data suggest? Preview Preview O Female and male servers work about the same number of hours Male servers work more hours O Female servers work more hours

Answer 1

Excel add-in (Mega Stat) procedure: Step 1: In EXCEL, Select Add-Ins> Mega Stat > Hypothesis Tests. Step 2: Choose Compare Two Independent Groups. Step 3: Choose Summary Input Step 4: In Group 1, enter B1:B4 (Select ranges with label mean, SD, n). Step 5: In Group 2, enter D1:D4 (Select ranges with label mean, SD, n). Step 6: Enter 0 Under Hypothesized difference. Step 7: Check t-test (unequal variance), enter Confidence level as 80.0 Step 8: Choose not equal in alternative. Step 9: Click OK. Excel add-in (Mega Stat) output:

Hypothesis Test: Independent Groups (t-test, unequal variance) Female Male 37 3 27 mean 4 std. dev. 33 df 10.000 difference (Female Male) 1.119 standard error of difference 0 hypothesized difference 8.537 confidence interval 80% lower 11.463 confidence interval 80% upper 1.463 margin of error Lower bound on CI 8.537 Upper bound on CI 11.463 It is 80% confident that the confidence interval does not contain the difference in means 0 then fail to reject the mull hypothesis, Therefore, female and male servers work about the same number of hours