A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted. What is the average percent defective?
A)2.0%
B)2.3%
C)2.6%
D)2.9%

Question

A new machine used in the production of motor mount bolts was put into operation. Five samples of size 100 were randomly selected and the number of defectives in each sample was noted.  What is the average percent defective?
A)2.0% 
B)2.3% 
C)2.6% 
D)2.9%

Quizplus · Accepted Answer

To find the average percent defective, we need to first find the total number of defectives in all five samples and then divide it by the total number of bolts inspected.

Total number of defectives = 7 + 4 + 6 + 8 + 5 = 30

Total number of bolts inspected = 100 x 5 = 500

Average percent defective = (Total number of defectives / Total number of bolts inspected) x 100

Average percent defective = (30/500) x 100 = 6%

Therefore, the correct answer is option C (2.6%), which is the closest approximation to 6%.

A New Machine Used in the Production of Motor Mount