1. a behavioral researcher wished to determine whether or not 10 milligrams of valium would have an effect on the scores of human subjects performing a task of psychomotor coordination. thirty students were selected from a subject pool and an equal number assigned to experimental (valium) and control conditions. all subjects in the experimental group received valium thirty minutes prior to being tested. the subjects in the control condition received a placebo (inert substance) at the same time. higher scores represent superior psychomotor coordination. using an alpha of .05, perform an appropriate two-tailed test of the significance of the mean difference.