Question

In testing circuit boards, a quality control

specialist found 3 out of 250 boards to be
defective. Predict how many defective circuit
boards may be expected out of the next
1,750 boards?

Answer 1

21

Explanation:

To find the number of defective items in a sample size n, the number is given by

E=np

Where p is the probability and n is the sample size.

Probability is given as 3/250=0.012

Sample size is given as 1750 boards

By substituting 0.012 for p and 1750 for n then the expected defective boards will be

E=0.012*1750=21

Therefore, it is likely that 21 boards are defective.