Question

A quality control inspector found 9 defective machine parts out of 500 manufactured.a) What percent of the machine parts manufactured were defective? b) What percent of the machine parts manufactured were NOT defective?

Answer 1

a) In order to calculate what percent of the machine parts manufactured were defective, you proceed as follow:

divide the defective machine between the total number of machines:

9/500 = 0.018

next, you multiply the previous result by 100:

0.018 x 100 = 1.8%

Hence, 1.8% of the total number of machines were defective

b) In this case you have:

subtract total machine and defective ones:

500 - 9 = 491

divide the previoues result by the number of toal machine:

491/500 = 0.982

multiply the previoues result by 100:

0.982 x 100 = 98.2

Hence, 98.2% of the total number of machine were NOT defective.