Question

Construct a control chart for the Lard-O example using 3 sigma limits if samples of size 10 are randomly selected from the process. The center line is ____. The standard deviation of the sample mean is ____. The UCL

Answer 1

The UCL is 3.636 and the LCL is 2.964.

Explanation:

The complete question is:

Construct a control chart for the Lard-O example using 3 sigma limits if samples of size 10 are randomly selected from the process. The center line is 3.3. The standard deviation of the sample mean is 0.112. The UCL = ____. The LCL = ____.

Solution:

The control chart is a graphical display used to study how a process changes over time. The data are plotted in time order.

The parts of a control chart are a central line for the average, an upper line for the upper control limit, and a lower line for the lower control limit.

These lines are formed using the historical data.

The information provided is:

Center line = m = 3.3

Standard deviation = s = 0.112

Compute the 3σ upper control limit as follows:

`\text{UCL}=m+3s`

`=3.3+(3* 0.112)\\=3.636`

Compute the 3σ lower control limit as follows:

`\text{LCL}=m-3s`

`=3.3-(3* 0.112)\\=2.964`

Thus, the UCL is 3.636 and the LCL is 2.964.