In a manufacturing plant a sample of five sheets is taken every one hour. The data collected on the thickness of these sheets is given below:

Sample Number

Thickness in millimeters (mm)

1

25

31

22

26

24

2

32

31

36

33

25

3

35

37

32

30

35

4

25

28

35

35

33

5

33

34

34

29

33

6

34

35

36

29

32

Required:

Draw a control chart for the mean and range and comment on whether the process is in control