Question

Three out of 200 machine parts were found to be defective.

About how many parts would be expected to be defective out of 2500 parts?

Answer 1

To answer the problem above, apply ratio and proportion. For every 200 machine parts, 3 are defective. The ratio that can be extracted from this is 200/3. Let x be the number of defective parts out of 2500 parts.
 
                                           (200 / 3) = (2500 / x)

From this equation, x equals 37.5. Therefore, there are approximately 38 defective parts.