Please write a clear explanation of how you got the answers. Thanks

I need to learn how to do it. I don't want just the answers, but how to get the answers.

Auto pistons are produced in a forging process, and the diameter is a critical factor that

must be controlled. From sample sizes of 10 pistons produced each day, the mean and.

the range of this diameter has been as follows:

a. What is the value of x?

b. What is the value of R ?

c. Prepare x and R charts.

d. Is the forging process in control? Why or why not?

DAY MEAN (MM) RANGE (MM)

1 156.9 4.2

2 153.2 4.6

3 153.6 4.1

4 155.5 5.0

5 156.6 4.5