Question

A group of screwdrivers produced in a day at a particular factory has a defect rate of 0.7%. Suppose a quality inspector randomly inspects 500 screwdrivers. Complete the following statement: The quality inspector should expect ____defective screwdrivers, with an error of ____. Group of answer choices

Answer 1

Answer: 3.5;0.4%

Explanation:

The number of defective screwdrivers that the quality inspector should expect would be calculated as:

= np

= 0.7% × 500

= 0.7/100 × 500

= 0.007 × 500

= 3.5

.

The error will be calculated as:

= √p(1-p)/n

= ✓0.007(1 - 0.007)/500

= 0.004

= 0.4%