Exercise Set 7.6: Standard Deviation Find the mean, the variance, and the standard deviation of the data set. Round your answer to the nearest hundredth. 1. The heights (at the shoulder) of different breeds of dogs: 600mm, 470mm, 170mm, 430mm, and 300mm. 2. The number of baskets scored by each team member of a high school basketball team: 8, 4, 6, 6, 7, 7, 9, 4, 8, 5. 3. The number of home runs from the top ten hitters during the 2005 Major League Baseball season: 51, 48, 47, 46, 45, 43, 41, 40, 40, 39. 4. The waiting times (in minutes) of several people at the DMV: 11, 17, 14, 12, 18, 13, 13, 26, 29, 18, 24, 17. 5. (a) The number of calories in a 1-ounce serving of several breakfast cereals: 135, 115, 120, 110, 110, 100, 105, 110, 125. (b) If 10 calories were added to each number, how would the mean and standard deviation be affected? 6. The waiting times (in minutes) at a McDonald’s drive-thru: 5, 3, 2.5, 8, 15, 4, 4.5, 6.5, 2, 9. (b) If 5 minutes were added to each waiting time, how would the mean and standard deviation be affected? 7. The exam scores are randomly selected from two different algebra 2 classes, which are given below. Which class has a lower variation of scores? Section 1: 42, 56, 60, 62, 67, 83, 81, 90. Section 2: 45, 58, 61, 75, 82, 87, 93, 94. 8. The daily attendance of Foothill students during a randomly chosen two week period: 965, 963, 970, 973, 952, 966, 980, 979, 973, 950. 9. The average high temperatures (in degrees Fahrenheit) are given in the table below. Which of the following three cities have the most consistent temperatures? To answer this question, calculate the variance and standard deviation for each city. City San Francisco San Diego Ventura
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct Nov Dec
57º
60º
62º
63º
64º
67º
67º
68º
70º
69º
63º
57º
65º
65º
66º
68º
68º
71º
75º
77º
76º
73º
69º
65º
69º
69º
71º
74º
75º
77º
81º
83º
82º
79º
74º
69º
