Question: A random sample of n = 16 scores is obtained from a population with a mean of μ = 80, and a treatment is administered to the sample. After treatment, the sample mean is found to be M = 82.

a. Assuming the sample variance is s2 = 64, compute the estimated d and r2 to measure the size of the treatment effect.

b. Assuming the sample variance is s2 = 1600, compute the estimated d and r2 to measure the size of the treatment effect.

c. Comparing your answers from parts a and b, how does sample variance influence measures of effect size?