Question

1. In an effort to increase production on an assembly line the factory manager decides to play music during the working day. For eight workers the number of items produced for a specific day is recorded below. Can the manager conclude that playing music has increased production? Let α = 0.05.

Worker                  1          2          3          4          5          6          7      8

Before                   6          8          10        9          5          12        9      7

After                      10        12        9          12        8          13        8      10

Answer 1

Worker	Before	After	d (After - Before)
1	6	10	4
2	8	12	4
3	10	9	-1
4	9	12	3
5	5	8	3
6	12	13	1
7	9	8	-1
8	7	10	3
		Total	16
		Average	= 2
		std dev	Sd = 2.07
		sample size n	8

Hypothesis:

H0: = 0

H1: > 0 claim (playing music has increased production) one tail right tailed test.

α = 0.05.

degrees of freedom = n-1 = 8-1 = 7

rejection criteria:-

critical value = t0.05,7 = 1.896

If the test statistic is greater than critical value then reject H0.

test statistic t = = 2/( 2.07/(sqrt(8))) = 2.733

Since test statistic > critical value we reject H0 and there is a sufficient evident that playing music has increased production.