The long jump is a track-and-field event in which a competitor attempts to jump a maximum distance into a sandpit after a running start. At the edge of the pit is a takeoff board. Jumpers usually try to plant their toes at the front edge of this board to maximize their jumping distance. The absolute distance between the front edge of the takeoff board and the spot where the toe actually lands on the board prior to jumping is called "takeoff error." Is takeoff error in the long jump linearly related to best jumping distance? To answer this question, kinesiology researchers videotaped the performances of 18 novice long jumpers at a high school track meet. (Journal of Applied Biomechanics, May 1995). The average takeoff error x and the best jumping distance (out of three jumps) for each jumper are recorded in the accompanying table and saved in the LONGJUMP file. If a jumper can reduce his or her average takeoff error by .1 meter, how much would you estimate the jumper's best jumping distance to change? On the basis of your answer, comment on the usefulness of the model for predicting best jumping distance.

Best Jumping Distance y (meters) Average Takeoff Error x (meters) Jumper 5.30 5.55 5.47 5.45 5.07 5.32 6.15 4.70 5.22 5.77 09 .19 .24 16 5 09 .12 09 09 .13 16 10 12 13 14 15 16 17 18 5.77 6.22 5.82 5.15 4.92 5.20 5.42 .13 04 07 04