Question

A manager at a factory finds that in a random sample of 250 watches, 3 are defective. Of the 7,500 watches from which the sample was chosen, about how many watches are not defective?

Answer 1

Answer: 7410 watches

Explanation:

From the random sample of 250 watches, 3 are defective. The percentage that's defective will be:

= 3/250 × 100

= 1.2%

Percentage that's not defective = 100 - 1.2 = 98.8%

Therefore, from the sample of 7500 watches, the number that's not defective will be:

= 98.8% of 7500

= 98.8/100 × 7500

= 7410

Therefore, 7410 watches aren't defective