A quality control engineer is interested in estimating the proportion of defective items coming off a production line. In a sample of 100 items, 55 are defective. The lower bound of a 99% confidence interval for the proportion of defectives is .

The lower bound of a 99% C.I for the proportion of defectives = 0.422

Step-by-step explanation:

From the given information:

The point estimate = sample proportion

= 0.55

At Confidence interval of 99%, the level of significance = 1 - 0.99

= 0.01

Then the margin of error

E = 0.128156

E ≅ 0.128

At 99% C.I for the population proportion p is:

= 0.55 - 0.128

= 0.422

Thus, the lower bound of a 99% C.I for the proportion of defectives = 0.422

i believe that is true.

step-by-step explanation:

hope my answer has you if not i'm sorry.