Question 11.1
11.1 Personal record for weightlifting. Bodyshop Athletics keeps a dry erase board for members to keep track of their personal record for various events. The “dead lift’’ is a weightlifting maneuver where a barbell is lifted from the floor to the hips. The following data are the personal records for members at Bodyshop Athletics in pounds lifted during the dead lift.
| Member | Weight | Member | Weight | Member | Weight |
|---|---|---|---|---|---|
| Baker, B. | 175 | G.T.C. | 250 | Pender | 205 |
| Baker, T. | 100 | Harper | 155 | Porth | 215 |
| Birnie | 325 | Horel | 215 | Ross | 115 |
| Bonner | 155 | Hureau | 285 | Stapp | 190 |
| Brown | 235 | Ingram | 165 | Stokes | 305 |
| Burton | 155 | Johnson | 175 | Taylor, A. | 165 |
| Coffey, L. | 135 | Jones, J. | 195 | Taylor, Z. | 305 |
| Coffey, S. | 275 | Jones, L. | 205 | Thompson | 285 |
| Collins, C. | 215 | LaMonica | 235 | Trent | 135 |
| Collins, E. | 95 | Lee | 165 | Tucker | 245 |
| Dalick, B. | 225 | Lord | 405 | Watson | 155 |
| Dalick, K. | 335 | McCurry | 165 | Wind, J. | 350 |
| Edens | 255 | Moore | 145 | Wind, K. | 185 |
| Flowers | 205 | Morrison | 145 |
Make a histogram of this distribution following the three steps described in Example 1. Create your classes using 75 ≤ weight < 125, then 125 ≤ 175, and so on.
Step 1: Divide the range of the data into classes of equal width. The data in the table range from 95 to 405, so we choose as our classes
75 ≤ weight < 125
125 ≤ weight < 175
. . .
375 ≤ weight < 425
Step 2: Count the number of individuals in each class. For example, there are three members in the first class, 12 members in the second class, and so on, up to one member in the final class.
629
Step 3: Draw the histogram. Mark on the horizontal axis the scale for the variable whose distribution you are displaying. That’s “Dead Lift Personal Record in Pounds” here. The scale runs from 75 to 425 because that range spans the classes we chose. The vertical axis contains the scale of counts. Here that is “Number of Members.” Each bar represents a class. The base of the bar covers the class, and the bar height is the class count. There is no horizontal space between bars unless a class is empty, so that its bar has height zero. The following figure is our histogram.
