Question

The overall distance traveled by a golf ball is tested by hitting the ball with Iron Byron, a mechanical golfer with a swing that is said to emulate the legendary champion, Byron Nelson. Ten randomly selected balls of two brands are tested and the overall distance measured. Assume that the variances are equal. The data follow: Brand 1: 288 276 287 271 283 271 279 275 263 267 Brand 2: 269 247 260 265 273 281 271 270 263 268 (a) Is there evidence to show that there is a difference in the mean overall distance of brands? Use α-005 a 0.05 Yes. (b) Calculate a 95% two-sided confidence interval on the difference in mean overall distance. Round your answer to one decimal place (e.g. 98.7. rts

Answer 1

The statistical software output for this problem is:

Two sample T confidence interval: : Mean of Brand 1 2: Mean of Brand 2 μ1-μ2 : Difference between two means with pooled variances) 95% confidence interval results: Difference Sample Diff. Std. Err. DF L. Limit U. Limit 9.3 3.8788601 18 1.1508174 17,449183

Hence,

95% confidence interval will be:

1.2 $\leq \mu_1 - \mu_2 \leq$ 17.4