In a sample of 78 widgets, 3 were defective. How many defective widgets would you expect in a sample of 390 widgets?
A) 15 widgets
B) 13 widgets
C) 36 widgets
D) 18 widgets

Question

Quizplus · Accepted Answer

The defect rate in the original sample is 3 defective widgets out of 78 total widgets. To find the expected number of defective widgets in a sample of 390, you can set up a proportion: (3 defective widgets / 78 total widgets) = (x defective widgets / 390 total widgets). Solving for x gives you 15 defective widgets.

In a Sample of 78 Widgets, 3 Were Defective