Question

A group of researchers wants to examine whether taking multiple practice quizzes improve scores on tests. They compare the exam scores for a sample of n₁ = 12 students who took multiple practice quizzes with the test scores of a sample of n₂ = 10 students who did not do any practice quizzes. Results of the study revealed that the practice quiz group had M₁ = 95, SS₁ = 52. The no quiz group had M₂ = 92, SS₂ = 48.

(a) Compute the degrees of fredom for an Independent-Measures T-test.

df =

(b) Determine the critical value of t for a two-tailed test at the 0.01 level of significance. (Use 3 decimal places.)

t-critical = ±

(c) Calculate the Pooled Variance: (Use 3 decimal places.)

S_P² =

(d) Calculate the Standard Error of the Difference in the Means: (Use 3 decimal places.)

S_(M1-M2) =

(e) Calculate the t statistic: (Use 3 decimal places.)

t =

(f) Should you reject or retain the null (H_o) for the two-tailed test with α = 0.01? And was there a statistically significant effect?

Fail to reject the null hypothesis, there is not a significant difference between the practice quiz and no quiz groups.

Reject the null hypothesis, there is not a significant difference between the practice quiz and no quiz groups.  

  Reject the null hypothesis, there is a significant difference between the practice quiz and no quiz groups.

Fail to reject the null hypothesis, there is a significant difference between the practice quiz and no quiz groups.

Answer 1