MATH 1281 Statistical Inference - Term 1,

A case study that deals with the eect of prior reputation on the evaluation of an instructor is presented in Question 11.1 in the book (Section 11.5). Students were exposed to either one of two conditions, C and P, and were asked to rate a lecture given by the instructor. It was found that the average rating among the 25 students that were exposed to condition C was 2.613 and the average rating among the 24 students that were exposed to condition P was 2.236. The sample standard deviations were 0.533 and 0.543, respectively. You want to construct a condence interval for the expected rating of students that were exposed to condition P. The condence level of the interval should be 80%. The quantile of the t-distribution that should be used for the construction is: (Assume a Normal distribution for the rating) Select one: a. qt(0.85,23) b. qt(0.925,24) c. qt(0.90,23) d. qt(0.925,23) The correct answer is: qt(0.90,23) MATH 1281 Statistical Inference - Term 1, 9/27/2018 Graded Quiz Unit 3 Question 2 Correct Mark 1.00 out of 1.00 Question 3 Correct Mark 1.00 out of 1.00 Information The condence interval with condence level of 80% for the expected rating of students that were exposed to condition P is: (Assume a Normal distribution for the rating. Choose the interval closest to the answer) Select one: a. [2.09, 2.38] b. [2.47, 2.76] c. [2.14, 2.33] d. [2.52, 2.71] The correct answer is: [2.09, 2.38