Question: Other research examining the effects of preschool childcare has found that children who spent time in day care, especially high-quality day care, perform better on math and language tests than children who stay home with their mothers (Broberg, Wessels, Lamb, & Hwang, 1997). Typical results, for example, show that a sample of n = 25 children who attended day care before starting school had an average score of M = 87 with SS = 1536 on a standardized math test for which the population mean is µ = 81.

a. Is this sample sufficient to conclude that the children with a history of preschool day care are significantly different from the general population? Use a two tailed test with α = .01.

b. Compute Cohen’s d to measure the size of the preschool effect.

c. Write a sentence showing how the outcome of the hypothesis test and the measure of effect size would appear in a research report.