To evaluate the effect of a treatment, a sample of n = 8 is obtained from a population with a mean of μ = 50, and the treatment is administered to the individuals in the sample. After treatment, the...

To evaluate the effect of a treatment, a sample of  n = 8 is obtained from a population with a mean of μ = 50, and the treatment is administered to the individuals in the sample. After treatment, the sample mean is found to be M = 55.

1. 
   

   Assuming that the sample variance is s^2 = 32 , use a two-tailed hypothesis test with α = .05 to determine whether the treatment effect is significant and compute both Cohen’s
   d
   and r^2 to measure effect size.

   
   


2. 
   

   Assuming that the sample variance is s^2 = 72 , repeat the test and compute both measures of effect size.

   
   


3. 
   

   Comparing your answers for parts a and b, how does the variability of the scores in the sample influence the outcome of a hypothesis test and measures of effect size?