Other research examining the effect 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. (Brobetg, Wessels, Lamb, & Hwang, 1997). Typical results, for example show that a sample of n = 25 children who attended 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 u = 81.

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

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