Question

A academic tutor wants to assess whether her remedial tutoring has been effective for her five students. She decides to conduct a related samples t-test and records the following grades for students prior to and after receiving her tutoring.

Tutoring
Before	After
2.5	3.1
2.6	3.0
3.1	3.6
3.0	3.2
2.8	3.6

(a) Test whether or not her tutoring is effective at a 0.05 level of significance. State the value of the test statistic. (Round your answer to three decimal places.)
t =  

State the decision to retain or reject the null hypothesis.

Retain the null hypothesis.Reject the null hypothesis.    

(b) Compute effect size using estimated Cohen's d. (Round your answer to two decimal places.)
d = 

Answer 1

The statistical software output for this problem is:

Summary statistics Column Mean Variance Std. de. Differences 5 0.52 0.052 0.22803509 Paired T hypothesis test: HOT - Mean of the difference between After and Before HH = 0 Hypothesis test results: Difference Mean Std. Err. DF After - Before 0.52 0.101980394 T-Stat 5.0990195 P-value 0.0035

Hence,

a) Test statistic = 5.099

b) d = 0.52/0.228 = 2.28