Question

Conduct an independent samples t-test (a.k.a., between-subjects design). Each sample should have at least n=8 individuals. What to turn in: 1. What is your research question? 2. State the null (Ho) and alternative (H1) hypotheses. 3. Conduct the hypothesis test using an alpha level of .05, and state your conclusion (Reject Ho/Fail to Reject Ho) regarding the original hypotheses. 4. Calculate and interpret a measure of effect size (est. Cohen's d or r2) and a 95% confidence interval.

data

Answer 1

I Session 'Two-Sample T-Test and Ci: score1, score2 Two-sample I for scorel vs score2 N Mean StDev SE Mean scorel 11 15.18 9.46 2.9 score2 11 21.82 6.68 2.0 Difference = mu (scorel) - mu (score2) Estimate for difference: -6.64 95% CI for difference: (-13.92, 0.65) T-Test of difference = 0 (vs not =): T-Value = -1.90 Both use Pooled StDev = 9.1892 P-Value = 0.072 DF = 20 НТВ

1) The research question is the average of the score 1 and score 2 are different or not.

2) Hypothesis

H0: mu1= mu2

H1: mu1=! mu2

3) alpha= 0.05

Here we get value=0.072 > 0.05

Hence fail to reject H0 .

4)

Cohen's d= mean2-mean1/pooled s.d

d= 21.82-15.18/8.1892

d=0.8108

Interpretation: This shows that two group means do not differ by more than 1-0.8108=0.1891 standard deviation.

95% confidence interval is (-13.92 ; 0.65)