A researcher selects a sample from a population with µ = 30 and uses the sample to evaluate the effect of a treatment. After treatment, the sample has a mean of M = 32 and a variance of s 2 = 6. If...

A researcher selects a sample from a population withµ = 30 and uses the sample to evaluate the effect of a treatment. After treatment, the sample has a mean ofM = 32 and a variance ofs
² = 6. If Cohen’sd is used to measure the size of the treatment effect, which of the following would have no effect on the value of Cohen’sd?

Group of answer choices