Two simulated sampling distributions that have a small amount of variability and little overlap provide some evidence of a real difference between the two population means.
What to look forInvestigating the distribution of the numerical difference between sample means can provide indication of a real difference between population means.
Sample AssessmentThe scores on an achievement test for 20 randomly selected boys and 20 randomly selected girls are collected. Which expressions provides some evidence that girls scored better than boys?
a) mean boys - mean girls > 0
b) mean boys - mean girls <>
c) mean boys - mean girls = 0
d) mean girls - mean boys <>