A company that manufactures baseball bats believes that its new bat will allow players to hit the ball 30 feet farther than its current model. The owner hires a professional baseball player known for hitting home runs to hit ten balls with each bat and he measures the distance each ball is hit to test the company’s claim. The results of the batting experiment are shown in the following table. Construct a 99% confidence interval for the true difference between the mean distance hit with the new model and the mean distance hit with the older model. Assume that the variances of the two populations are the same. Let Population 1 be the distances of balls hit with the new model baseball bat and Population 2 be the distances of balls hit with the old model. Round the endpoints of the interval to one decimal place, if necessary. Hitting Distance (in Feet)
New Model Old Model
297 286
274 262
274 265
210 273
218 232
288 277
225 258
227 237
249 236
259 270