You are the production manager for a part manufacturing company.There are 2 manufacturing locations, plant A and B. you suspectthere is a difference in the proportion of rejected parts that aremanufactured at Plant A as compared to plant B. for a week youobserved:
| Plant A | Plant B | total |
Rejected parts | 120 | 80 | 200 |
Acceptable parts | 1880 | 1920 | 3800 |
| 2000 | 2000 | 4000 |
The proportion of rejected parts was200/4000=5%. If there were no difference between the proportion ofrejected parts whether there were manufactured at either plant A orplant B then you would estimate:
| Plant A | Plant B | total |
Rejected parts | | | 200 |
Acceptable parts | | | 3800 |
| 2000 | 2000 | 4000 |
You decide to preform a chi squaredtest to determine if there is statistically a difference betweenthe proportion of rejected parts manufactured at plant A ascompared to the proportion of rejected parts manufactured at plantB.
- State your null and alternate hypothesis. B) at the 5% level ofsignificance, is there evidence of a difference between theproportions of rejected parts manufactured at plant A as comparedto plant B? based on your hypothesis test what is your conclusion?State your conclusion formally.
