2 Chapter Quiz 120 CHAPTER 2 Descriptive Statistics Take this quiz as you would take a quiz in class. After you are done, check your work against the answers given in the back of the book. 1. The data set represents the number of minutes a sample of 27 people exercise each week. 108 139 120 123 120 132 123 131 131 157 150 124 111 101 135 119 116 117 127 128 139 119 118 114 127 142 130 (a) Construct a frequency distribution for the data set using five classes. Include class limits, midpoints, boundaries, frequencies, relative frequencies, and cumulative frequencies. (b) Display the data using a frequency histogram and a frequency polygon on the same axes. (c) Display the data using a relative frequency histogram. (d) Describe the shape of the distribution as symmetric, uniform, skewed left, skewed right, or none of these. (e) Display the data using an ogive. (f) Display the data using a stem-and-leaf plot. Use one line per stem. (g) Display the data using a box-and-whisker plot. 2. Use frequency distribution formulas to approximate the sample mean and the sample standard deviation of the data set in Exercise 1. 3. The elements with known properties can be classified as metals (55 elements), metalloids (6 elements), halogens (5 elements), noble gases (6 elements), rare earth elements (30 elements), and other nonmetals (7 elements). Display the data using (a) a pie chart and (b) a Pareto chart. 4. Weekly salaries (in dollars) for a sample of construction workers are listed. 1100 720 1384 1124 1255 976 718 1316 749 1062 1248 891 969 790 860 1100 (a) Find the mean, median, and mode of the salaries. Which best describes a typical salary? (b) Find the range, variance, and standard deviation of the data set. (c) Find the coefficient of variation of the data set. 5. The mean price of new homes from a sample of houses is $180,000 with a standard deviation of $15,000. The data set has a bell-shaped distribution. Using the Empirical Rule, between what two prices do 95% of the houses fall? 6. Refer to the sample statistics from Exercise 5 and determine whether any of the house prices below are unusual. Explain your reasoning. (a) $225,000 (b) $80,000 (c) $200,000 (d) $147,000 7. The number of regular season wins for each Major League Baseball team in 2020 are listed. Display the data using a box-and-whisker plot. (Source: Major League Baseball) 43 25 26 26 23 27 31 32 36 40 30 26 35 31 26 26 29 24 29 29 22 36 19 35 25 37 33 28 35 34
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