Question

Researchers wanted to determine if the psychological profile of healthy children was different than for children suffering from recurrent abdominal pain (RAP) or recurring headaches. A total of 210 children and adolescents were studied and their psychological profiles were graded according to a child behavior checklist. Children were stratified in two age groups: 4 to 11 years and 12 to 18 years. The results of the study are summarized in the accompanying table. Complete parts (a) through (f) below. B Click the icon to view the summary of the results. Summary of the results (a) Compute the sample standard deviations for each group. The sample standard deviation for the control group is sc= (Round to one decimal place as needed.) Sample mean Sample variance Control group 11.8 21.5 The sample standard deviation for children suffering from recurrent abdominal pain (RAP) is SR=0 RAP 70 9.0 13.1 (Round to one decimal place as needed.) Headache 70 12.5 8.4 The sample standard deviation for children suffering from recurring headaches is sh = 0 (Round to one decimal place as needed.) Print Done (b) What sampling method was used for each treatment group? Why? 70 O A. Stratified sampling, because the researchers wanted to be sure that both children and adolescents were represented in the samples OB. Cluster sampling, because it eliminates bias from the researcher and subjects OC. Simple random sampling, because the researchers wanted to be sure that the distributions of the sample means were approcimately normal OD. Systematic sampling, because it decreases the sample variabilities (c) Use a two sample t-test for independent samples to determine if there is a significant difference in mean behavior scores between the control group and the RAP group (assume that both samples are simple random samples). Use a = 0.05. What are the null and alternative hypotheses being tested? O A. Ho: Hc2 HR and Hy: Hc<HR

Answer 1