7. Johnny Crabcakes wants to compare the average Exam 1 grades between two class

Question

7. Johnny Crabcakes wants to compare the average Exam 1 grades between two classes (sections 102 and 103). But first Johnny has to decide what test he should run in Excel. Use the output in Figure 1 and a.05 significance level to guide Johnny on what the appropriate test is. Note: The output in Figure 1 was generated using a.05 significance level. F-Test Two-sample for variances 103 (n-30)102 (n-35 Mean Variance Observations df 82.16666667 81.14285714 294.2816092 172.1848739 35 34 30 29 1.709102562 0.066982859 1.802003383 p(F | one-tail F Critical one-tall Figure 1: Comparing the variances of Stats II Exam l grades between section 103 and 102 a. Johnny should pool the variances and run an "equal variance t-test" b. Johnny should not pool the variances and run an "unequal variance t-test" c. Johnny should run a z-test for two proportions d. Johnny should run a t-test for two dependent samples

Explanation / Answer

7. Since here smaple size are large enough and he wants to compare the mean not variances so Jhony should pool the variances and should run an equal variance t-test. So option a is correct.

8. We are assuming that population variances are not equal so option b is correct.

9.

Criticl value approach:

Since t-stat value (0.593) is less than one tailed critical value(1.321) and test is right tailed so we fail to reject the null hypothesis. That is result is not siginificant.

P-value approach:

Since P value (0.280)-one tailed is greater than 0.10 (level of siginificance) so we fail to reject the null hypothesis. That is result is not siginificant.

Hence, option a is correct.

Related Questions

Navigate

• Browse (All)
• Browse 7
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.