91影视

Data values are given for eightyears on the energy consumed (in kWh) in a two-month period.

The sample size for each of the eightyears is equal to 6.

For constructing the R chart, the values of the central line\(\bar R\), the lower control limit (LCL), and the upper control limit (UCL) need to be determined.

Referring to Exercise 1 CRE, the values are as follows:

\(\begin{aligned}{l}\bar R = 1729\;{\rm{kWh}}\\LCL = 0\;{\rm{kWh}}\\UCL = 3465\;{\rm{kWh}}\end{aligned}\)

Follow the given steps to construct the R chart:

• Mark the values 1, 2, ..., 8 on the horizontal axis and label the axis as 鈥淪ample.鈥�
• Mark the values 0, 500, 1000, 鈥�., 3500 on the vertical axis and label the axis as 鈥淪ample Range.鈥�
• Plot a straight line corresponding to the value 鈥�1729鈥� on the vertical axis and label the line (on the left side) as 鈥淺(\bar R\)=1729.鈥�
• Plot ahorizontal line corresponding to the value 鈥�0鈥� on the vertical axis and label the line as 鈥淟CL=0.鈥�
• Similarly, plot a horizontal line corresponding to the value 鈥�3465鈥� on the vertical axis and label the line as 鈥淯CL=3465.鈥�
• Mark the following sample ranges on the graph corresponding to the sample number and join the dots using straight lines:

The following R chart is plotted:

The chart does not seem to show any of the three out-of-control criteria.

Thus, it can be concluded that the process variation is within statistical control.