Reference no: EM132527665

A manufacturer of groundnut paste has a specification of 50-52% oil content for the raw groundnuts. Table 2 shows data on groundnuts supplied over a 2 week period.

Plot X-bar and R charts using the data

Oil content %
Days S1 S2 S3 S4
1 48.5 48.7 49.1 48.8
2 51.2 51.8 52.1 51.9
3 51.3 51.9 51.5 51,7
4 51.9 51.7 52.0 51.6
5 50.8 50.4 50.9 50.9
6 50.8 50.6 50.9 50.7
7 51.9 51.6 51.9 51.8
8 49.1 49.0 48.9 48.8
9 51.2 51.4 51.4 51.5
10 51.9 51.9 51,7 51.9
11 47.9 47.6 47.9 48.0
12 50.2 50.7 50.6 50.9

i. Calculate the subgroup mean (X) for each subgroup

ii. Calculate the subgroup range for each subgroup

iii. Calculate X and R

iv. Find the appropriate control chart constants to use in calculating the control limits

v. Calculate the UCL and LCL for the X-bar chart and the R-chart.

vi. Plot the X-Bar and R-charts

vii. Are there any out of control points? If yes, calculate the revised mean and control limits for both the X-bar and R-charts.