CK-12 Basic Probability and Statistics - A Short Course

http://www.ck12.org Chapter 6. Measures of Central Tendency - Basic

TABLE6.5:

Number Of Tails Frequency

4 3

3 23

2 16

1 17

0 5

8. A manufacturer of light bulbs had their quality control department test the lifespan of their bulbs. Forty-two
   bulbs were randomly selected and tested, with the number of hours they lasted listed below.

100 125 137 167 158 110 142

163 135 146 134 121 163 168

114 128 164 152 158 143 162

137 126 149 168 152 129 156

153 162 168 144 124 119 147

147 152 162 159 157 141 160

If the manufacturer wants to offer a warranty with the light bulbs, what is the mean number of hours that the

bulbs lasted?

9. The following data represents the height in centimeters of 32 Grade 10 students. What is the mean height of
   the students?

158 169 156 174 180 163 162 159

167 179 181 167 170 164 172 175

161 174 176 182 173 168 160 183

157 165 174 169 180 176 168 180

10. Miss Smith gave her class a surprise quiz and gave it a value of 15 points. The following frequency table
    shows the results:

TABLE6.6:

Quiz Mark Number of Students

0 0

1 0

2 0

3 0

4 1

5 2

6 2

7 4

8 5

9 6

10 3

11 4

12 1

13 0

14 1

15 0