Question

Sample means and ranges were obtained for five samples of 10 units per sample from a production process. Assume the process was considered to be in control during the period these samples were collected. The results are as follows:

Sample Mean Range
1 10.58 0.23
2 9.97 0.25
3 9.99 0.21
4 10.23 0.28
5 10.23 0.28

Required:
What is the central line of the X chart for this process

Answer 1

10.20

Step-by-step explanation:

Given the data :

Sample___ Mean ____Range

1 ________10.58 _____0.23

2________ 9.97 _____ 0.25

3 ________9.99 _____ 0.21

4 ________10.23_____ 0.28

5 ________10.23 _____0.28

The central line of the X_chart :

CL = xbar = Σx / n

CL = central line

x = mean values of the samples

n = number of samples

xbar = (10.58 + 9.97 + 9.99 + 10.23 + 10.23) / 5

xbar = 51 / 5

xbar = 10.20

Central line = 10.20