A social psychologist records the number of outburst in a sample of different classrooms at a local school. based on the statement below, what are the sample size, decision (retain or reject the null hypothesis), and effect size in the study? The number of outbursts among students at this local school (M = 3) was significantly less than that in the general population, t(39) = 4.19, p < .05 (d = 0.25).