preparation products on the market Study Focus and Prepara A

Last updated: 5/21/2023

preparation products on the market Study Focus and Prepara A researcher in the Education department at a nearby university wants to estimate the difference between the mean score on the test by users of StudyFocus and the mean score on the test by users of Prepara The researcher obtains the scores on the test from a random sample of 16 users of StudyFocus and a random sample of 14 users of Prepara These samples are chosen independently For the users of StudyFocus their sample mean is 507 8 with a sample variance of 5808 7 For the users of Prepara their sample mean is 557 4 with a sample variance of 634 1 Assume that the two populations of scores are approximately normally distributed Let be the population mean score on the test by the users of StudyFocus Let 1 be the population mean score on the test by the users of Prepara Construct a 95 confidence interval for the difference Then find the lower and upper limit of the 95 confidence interval Carry your intermediate computations to three or more decimal places Round your answers to two or more decimal places If necessary consult a list of formulas Lower limit Upper limit X