Question

Suppose that 8% of all cars produced at Plant A have a certain defect, and 5\% of all cars produced at Plant B have this defect. A quality control manager takes separate random samples of 150 cars from each plant. The manager will then look at the difference (A - B) between the proportions of cars with the defect in each sample. What will be the shape of the sampling distribution of the difference in sample proportions, and why?

Answer 1

Answer: D

Not normal, because we expect fewer than 10 defective cars in Plant B.
`.05*150=7.5`

Step-by-step explanation: Khan Answer

Answer 2

The answer is "Choice d"

Explanation:

Please find the complete question in the attached file.

Faulty factory cars in a plant
`A = 8\% \ of\ 150 \ = 12 > 10`

Faulty factory cars in a plant
`B = 5\% \ of \ 150 = 7.5 < 10`

This condition of the normal distribution is not met so because the number of negative cars from plant B is less than 10, that's why the choice d is correct.