The following samples have been taken from an on-going process. Use these values
ID: 3360853 • Letter: T
Question
The following samples have been taken from an on-going process. Use these values to create both an X bar and an R chart, and then answer the questions below.
Sample 1: 56 48 53 58 52
Sample 2: 50 59 57 56 54
Sample 3: 61 59 56 55 58
Sample 4: 57 51 52 57 50
Sample 5: 52 49 57 55 56
Sample 6: 56 55 60 58 55
What is the value of the centerline for an X bar chart? (Round to two decimal places)
The upper control limit for the X bar chart is:
The lower control limit for the X bar chart is:
The upper control limit for the R chart is:
The lower control limit for the R chart is:
Explanation / Answer
The statistical software output for this problem is:
Control chart results:
Xbar Chart results:
Upper control limit = 59.027267
Center line = 55.066667
Lower control limit = 51.106067
R Chart results:
Upper control limit = 16.4328
Center line = 8.2
Lower control limit = 0
Hence,
Centerline for x bar chart = 55.07
The upper control limit for the X bar chart = 59.03
The lower control limit for the X bar chart = 51.11
The upper control limit for the R chart = 16.43
The lower control limit for the R chart = 0