Question

a manufacturer produces screws. as a quality check, a random sample of 250 screws are tested for every 1000 screws produced. it is allowed for up to 3 screws per sample to not meet the specifications. what is the maximum number of screws that can be expected to not meet the specifications in a box of 4,750 screws? ① 57 ② 143 ③ 1,188 ④ 1,585

Explanation:

Step1: Calculate the number of samples

The number of samples \(n=\frac{4755}{250}=19.02\approx19\) (since we can't have a fraction of a sample, we take the whole - number part).

Step2: Calculate the maximum number of non - meeting specifications screws

Since up to 3 screws per sample can not meet the specifications, the maximum number of non - meeting specifications screws \(=3\times19 = 57\).

Answer:

A. 57