Hi guys, i was given the following problem:

The mean diameter of a batch of bolts is 9.711mm and the standard deviation of the batch is 0.126mm

The tolerance for this batch of components is 9.73mm to 9.97mm.

In a batch of 2000 bolts, determine the following:

a) The percentage of bolts rejected assuming the bolts are normally distributed.

My answer:

(9.97 - 9.73) / 0.126 = 1.90

1.90 Corresponds to: 0.9713

1 - 0.9713 = 0.0287

(Little less than 3% are rejected)

0.0287 x 2000 = 57.4

= 57 rejected out of 2000

Can anybody tell me if i'm right?