University of the PeopleMATH 1281Graded Quiz Unit 3

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A case study that deals with the e×ect 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 co... nditions, 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 conÒdence interval for the expected rating of students that were exposed to condition P. The conÒdence 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, 2018-20199/27/2018 Graded Quiz Unit 3 https://my.uopeople.edu/mod/quiz/review.php?attempt=1415917 2/13 Question 2 Correct Mark 1.00 out of 1.00 Question 3 Correct Mark 1.00 out of 1.00 Information The conÒdence interval with conÒdence 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] The conÒdence interval with conÒdence level of 75% for the variance of the 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. [0.404, 0.805] b. [0.250, 0.374] c. [0.219, 0.437] d. [0.460, 0.689] The correct answer is: [0.219, 0.437] ConÒdence intervals are computed for the expectation and the variance of a measurement on the basis of 15 observations. The conÒdence interval are constructed under the assumption that the measurement has a Normal distribution. In reality, the distribution of the observations is the Exponential(1/3) distribution. Recall that the expectation of the measurement is 3 and the variance is 9. Use simulations to answer the following questions:9/27/2018 Graded Quiz Unit 3 https://my.uopeople.edu/mod/quiz/review.php?attempt=1415917 3/13 Question 4 Correct Mark 1.00 out of 1.00 Question 5 Incorrect Mark 0.00 out of 1.00 Information Consider a conÒdence interval for the expectation with a nominal conÒdence level of 95%. The actual conÒdence level is: (Select the closest number.) Select one: a. 0.75 b. 0.85 c. 0.90 d. 0.95 The correct answer is: 0.90 Consider a conÒdence interval for the variance with a nominal conÒdence level of 95%. The actual conÒdence level is: (Select the closest number.) Select one: a. 0.75 b. 0.85 c. 0.90 d. 0.95 [Show More]

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