Homework SourseTo determine whether there are differences in the quality of
To determine whether there are differences in the quality of electronic items produced by 3 daily workshifts in factory A, a sample of 600 items was selected and each was classified as either flawed or perfect.
Shift
Condition
1
2
3
Perfect
240
191
139
Flawed
10
9
11
Is the quality of items related to the work shift? Use all testing methods at 5% significance level.
| Shift | |||
| Condition | 1 | 2 | 3 |
| Perfect | 240 | 191 | 139 |
| Flawed | 10 | 9 | 11 |
Solution
H0: Quality of items are independent of work shift.
Ha: Quality items are related to work shift.
Two sided test.
?2 = 2.351, df = 2, ?2/df = 1.18 , P(?2 > 2.351) = 0.3087
Alpha = 0.05
As p >0.05, accept null hypothesis.
Quality of items are independent of work shift.
| quality of electronic items produced by 3 daily workshifts i | ||||
| shift I | ii | iii | ||
| Perfect | 240 237.50 ( 0.03) | 191 190.00 ( 0.01) | 139 142.50 ( 0.09) | 570 |
| Flawed | 10 12.50 ( 0.50) | 9 10.00 ( 0.10) | 11 7.50 ( 1.63) | 30 |
| 250 | 200 | 150 | 600 |
