A sample of difference scores has a mean of MD = 5 with a variance of s2 = 100 . If effect size is ...

A sample of difference scores has a mean of MD = 5 with a variance of s2 = 100 . If effect size is measured using Cohen's d, what is the value of d?
 
  a. 5/10
  b. 5/100
  c. 25/100
  d. Cannot determine without knowing the sample size

Question 2

If a repeated-measures study shows a significant difference between two treatments with  = .01, then what can you conclude about measures of effect size?
 
  a. The value of Cohen's d is large.
  b. The percentage of variance explained (r2) is large.
  c. Both Cohen's d and r2are large.
  d. A significant effect does not necessarily mean that the effect size will be large.

Question 3

A repeated-measures study comparing two treatments with a sample of n = 4 participants produces MD = 3 with SS = 48 for the set of difference scores. What is the repeated-measures t statistic for these data?
 
  a. 3/3 = 1.73 c. 3/4 = 0.75
  b. 3/2 = 1.50 d. 3/16 = 0.19