Minitab Assignment Example | Topics and Well Written Essays - 250 words - 1

Minitab - Assignment Example To determine whether the wording of the cover letter influences the response rate, three different cover letters were used in a survey of students at a Midwestern university. Suppose that each of the three cover letters accompanied questionnaires sent to an equal number of randomly selected students. Returned questionnaires were then classified according to the type of cover letter (I, II, or III). Use the accompanying data to test the hypothesis that the true proportions of all returned questionnaires accompanied by cover letters I, II, and III are the same. Use a 0.05 significance level. As shown in Minitab output, all expected frequencies are greater than 1 and no expected frequency is less than 5. Furthermore, as stated in the problem, the sample is a simple random sample. Therefore, all the assumptions of the test are met. At the 5% significance level, the data provide sufficient evidence to conclude that the hypothesis that the true proportions of all returned questionnaires accompanied by cover letters I, II, and III are the same. 2. A survey was conducted in the San Francisco Bay area in which each participating individual was classified according to the type of vehicle used most often and city of residence. A subset of the resulting data is given in the accompanying table. Do the data provide convincing evidence of an association between city of residence and vehicle type? Use a significance level of 0.05. You may assume that it is reasonable to regard the sample as a random sample of Bay area residents. As shown in Minitab output, all expected frequencies are greater than 1 and no expected frequency is less than 5. Furthermore, as stated in the problem, it is reasonable to regard the sample as a random sample of Bay area residents. Therefore, all the assumptions of the test are met. Standardized residuals greater than 2 in absolute value provide evidence