Question

2) A large corporation experiments with different types of background music to assess the effects on the productivity of secretaries in a typing pool. Over the course of several days, it uses soft background music, rock music, classical music, and no music and measures the number of letters typed by random selections of four secretaries in 2-hour periods. The results are as follows: 10 +4+1+216 Points) Soft: 15 18 22 17 13 20 16 15 15 19 24 18 14 23 17 14 Rock: Classical None a) Test whether there is any significant difference among the means of the number of letters typed per 2-hour period for the four types of background music at the 5% level of significance. Show all four steps of the testing procedure and show complete work. Also compute samples means and the P-value. b) Calculate the variances of the number of letters typed per 2-hour period and see whether the assumption of common (equal) variance ơ 2 seem to be satisfied for these four types of background music c) If post-hoc tests such as Bonferroni and Tukey, need to be conducted on the means of the number of letters typed per 2-hour period for the four types of background music at the 5% level of significance, how many pairs of means need to be tested? d) Is it necessary to conduct post-hoc tests in this problem? Why or why not?

Answer 1

WEDNESDAY Wk 19 126-239 22 % u * 22一一1 t 5 ly 23-17. 1.4 12 200K id 280

5 23 24 25 26 27 28 127-238 Wk 19 22 + 80 il 56)- 4902 f-276个10244 1

08 MAY FRIDAY 2015 Wk 19 128-237 n- 16 E 12

2015 10 SATURDAY 59

MONDAY 2015 2119 2 25 2 2 Wk 20 131-234 10 L0.5 2 12 TV 1210 3.5

7 3 3 6 7 2 1 13 14 24 11 19 3 21 12 MAY TUESDAY 2 2 28 as 2015 132-233 Wk 20