Homework SourseThe following sample information shows the number of defecti
The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of four days last month.
At the .05 significance level, can we conclude there are more defects produced on the day shift?
| The null and alternate hypotheses are: | |||||||||||||||||||
| H0 : ?d ? 0 | |||||||||||||||||||
| H1 : ?d > 0 | |||||||||||||||||||
| The following sample information shows the number of defective units produced on the day shift and the afternoon shift for a sample of four days last month.
|
Solution
(1) The degree of freedom =n-1=4-1=3
Given a=0.05, the critical value is t(0.05, df=3)=2.353 (from student t table)
Reject H0 if t >2.35
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(2)
test statistic is
t= mean difference/(s/vn)
=1.732
| 13.000 | mean Day shift | |||
| 11.500 | mean Aternoon shift | |||
| 1.500 | mean difference (Day shift - Aternoon shift) | |||
| 1.732 | std. dev. | |||
| 0.866 | std. error | |||
| 4 | n | |||
| 3 | df |
