A Sample Is Selected from a Population with µ =

Essay

A sample is selected from a population with µ = 80.After a treatment is administered to the individuals,the sample mean is found to be M = 75 and the variance is s2 = 100.
a. If the sample has n = 4 scores, then calculate the estimated standard error and determine whether the sample is sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with α = .05.
b. If the sample has n = 25 scores, then calculate the estimated standard error and determine whether the sample is sufficient to conclude that the treatment has a significant effect? Use a two-tailed test with α = .05.
c. Describe how increasing the size of the sample affects the standard error and the likelihood of rejecting the null hypothesis.