@

the two variance are equal

Problem 1 (5.0 points). A men's softball league is experimenting with a yellow base- ball that is easier to see during night games. One way to judge the effectiveness is to count the number of errors. In a preliminary experiment, the yellow baseball was used in 10 games and the traditional white baseball was used in another 10 games. The number of errors in each game was recorded and is listed here. Yellow: 5, 2, 6, 7, 2,5, 3, 8,4,9 White: 7,6,8,5,9,11,8,3,6,10 1. Estimate with 90% confidence the difference of the mean number of errors between the yellow baseball and the white baseball. 2. Can we infer that there are fewer errors on average when the yellow ball is used at 5% level of significance