If a researcher suspects that the strength of the relationsh

If a researcher suspects that the strength of the relationship between two variables in the population is .25 as indexed by eta-squared, what sample size should he use in a study involving two correlated groups and an alpha level of .05, directional test, in order to achieve a power of .90?

Solution

correlated groups t test is used when the samples aredependent; that is, when there is only one sample that has beentested twice (repeated measures) or when there are two samples thathave been matched or \"paired\".

here correlated groups t test isused