Question: A machine operation requires close tolerance on a certain part automobile engines. the current specification for this measurement is 3.0 cm +/- .001.

The quality control procedure is to take a sample of size 4 and measure each of the parts. On the basis of past samples of size 4, \(\bar{\bar{X}}=3\) and R(with a 1 line on top)= .0020.

a. Construct an average and range chart for this part.

b. On the basis of the following data, is the process in control

Sample 1 2 3 4 5

X 3.0005 2.9904 3.0010 3.0015 3.008
R 0.0024 0.0031 0.0010 0.0040 0.0010


c. is the process running outside of its specifications.