298 CHAPTER 9 Introduction to the t Statistic T home with their mothers (Broberg, Wessels, Lamb, & a standardized well-being questionnaire for which the general population has an average The well-being scores for this sample are as follows: 38, 37, 41, 35, 42, 40, 33, 33, 36, 38, 32, 39. a. On the basis of this sample, is well-being for frequent movers significan tly different from well- being in the general population? Use a two-tailed test with o Hwang, 1997). In a typical study, a researcher obtains 10 children who attended day care Score of 40. a sample of n before starting school. The children are given a stan dardized math test for which the population mean is 50. The scores for the sample are as follows: 53, 57, 61, 49, 52, 56, 58, 62, 51, 56. 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 a = .01. 05 b. Compute the estimated Cohen's d to measure the size of the difference. c. Write a sentence showing how the outcome of the hypothesis test and the measure of effect size would appear in a research report. 23. Research examining the effects of preschool child- care 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 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. IS iw