Math 50 - Section 4.2 Name Anastasive Chopra Measures of the Spread Instructor Date_ 1. The following data set represents the duration of wooden roller coaster rides (in seconds) in Ohio. 63 90 90 93 105 140 250 Include units in all responses and where necessary, round to one decimal place. Find each of the following: Range Standard Dev. 5 5 95 Variance S- 35 22. 1 111 56 2. The data below gives the number of credit hours (CH) a sample of students were enrolled in during one semester. 16 10 11 13 13 15 15 13 15 17 13 14 11 12 14 14 16 12 15 11 13 10 13 10 15 15 16 8 13 16 14 12.5 14 18 4 13 11 13 5 a. Find each of the following values for this data set. Where necessary round to one decimal place. Include units in all responses. X = Med = M = R = S = S 2 = b. Complete the frequency table for this data set. Number of Number of Credit Hours Students 4-5 6-7 8 - 9 10-11 12-13 14-15 16-17 18-19 83c. Using your frequency table, construct a histogram for this data set. -............ ....... ...i.... ..................j.... ................... d. Does the Empirical Rule apply? Why or why not? Briefly explain. e. According to the Empirical Rule, approximately what percentage of the observations in this data set fall within one standard deviation of the mean? f. Use the data set to determine the actual percentage that fall within one standard deviation of the mean. This will involve you calculating a percentage. g. Is the observation for the student enrolled in 4 credit hours unusual? Why or why not? Briefly explain h. A student concludes that the mean and standard deviation describe the center and the spread of the numbers of credit hours for all students enrolled at the college. What would you tell this student? Briefly explain. 84