STAT 100 - C40 Elementary Statistics for Applications Assignment - 2 Due on 20 May, 2020 by 1 pm Total Marks: 25 Please upload your solutions in UR courses MARKS 1. The following data represent the...

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STAT 100 - C40 Elementary Statistics for Applications Assignment - 2 Due on 20 May, 2020 by 1 pm Total Marks: 25 Please upload your solutions in UR courses MARKS 1. The following data represent the social ambivalence scores for 14 people as measured by a[9] psychological test. (The higher the score, the stronger the ambivalence.) 18 12 11 4 5 7 8 5 8 10 11 9 16 14 Find the interquartile range, five number summary and sketch a box and whisker plot for the data. Find if there are any outlier(s)? 2. A social skills training program was implemented with seven mildly challenged students in[10] a study to determine whether the program caused improvement in pre/post measures and behavior ratings. For one such test, the pre - and posttest scores for the seven students are given in the table. Subject Pretest, x Posttest, y Earl 102 112 Ned 90 88 Jasper 112 122 Charlie 106 98 Tom 91 104 Susie 91 94 Lori 89 98 a) Calculate the linear correlation coefficient, r. Describe the relationship. b) Calculate the line-of-best-fit(linear regression line). c) Estimate the post test score if the pretest score was 98. 3. The linear correlation coefficient of a set of data points is -0.85.[2] a) Is the slope of the regression line positive or negative? b) Determine the coefficient of determination. 4. A regression analysis between sales (y in $1000) and advertising (x in $100) resulted in the[2] following least-squares line: ŷ = 82 + 7x. Given this information, if advertising costs were $900, what could we reasonably expect the amount of sales (in dollars) to be? 5. A regression analysis between weight (y in kg) and height (x in cm) resulted in the following[2] least-squares line: ŷ = –20 + 0.5x. Taking this into consideration, if the height is increased by 1 cm, what does this imply about the change in the weight, on average? 1