Business Statistics

Chapter 17 | Statistical Quality Control 667

FIGURE 17.27

x

control chart (using range)

produced using SPSS

FIGURE 17.28

x

control chart (using

standard deviation) produced

using SPSS

Construct an R chart for the data given in Example 17.5.

Solution Figure 17.29 is the SPSS output exhibiting R chart for the data given in Example

17.5. The control limit, upper control limit, and lower control limit can be com-

puted by the formula given below. For n = 7, the value of D

3

is equal to 0.076 and

the value of D

4

is equal to 1.924.

Example 17.6

BS_CH_17.indd 667 6/19/2009 9:30:21 PM

668 Business Statistics

Control limit (CL) =

R

= 0.2114

Lower control ...