A grinding machine will be qualified for a particular task i

A grinding machine will be qualified for a particular task if it can be shown to produce less than 8% defective parts. In a random sample of 300 parts, 12 were defective. On the basis of these data, can the machine be qualified?

Solution

12 / 300 = 0.04 = 4%

the machine is qualified because it can be shown to produce less than 8% defective parts