Question

Suppose administrators at a large school district decide to institute mandatory study halls at their middle schools in an effort to boost their students' academic performance. After one year, a guidance counselor decides to test whether students' grade point averages (GPAs) have improved compared to the previous school year. The counselor selects a random sample of 25 eighth-graders from throughout the district who were also enrolled in the district for seventh grade. He records their GPAs for grades seven and eight, and for each student, calculates the difference between the two. The counselor's data is summarized in the given table. Variable description seventh grade GPA eighth grade GPA difference (8th - 7th) Sample mean *7 = 2.89433 Kg = 2.96493 x = 0.07060 Sample standard deviation S7 = 0.51053 S8 = 0.57332 s = 0.23495 Standard error estimate SE7 = 0.10211 SE; = 0.11466 SE = 0.04699 The counselor plans to use this information to conduct a matched-pairs t-test of the null hypothesis Ho:u= 0 against the alternative hypothesis Hų:u > 0, where u is the mean change in students' GPAs after mandatory study halls were instituted. What is the t-statistic for the counselor's test? Round your answer to three decimal places. t = 1.502

Answer 1

o.07060 stedishc =0-S02 pralue, p p-Pltt4o Sigivtficame eud, d-0 -05 Simce P value 0.3101 70.05, wefaj t ee the ull kupothesis . That is there is insnfent ouldenca that the meam difeera tn GPA fo Seuenth guadet eigdgrae for all ex gradun is eatu han O 31e121-0-3 we fai t Aed o o