SCENARIO 18-9
the Manufacturer of Canned Food Constructed Control Charts

SCENARIO 18-9
The manufacturer of canned food constructed control charts and analyzed several quality
characteristics. One characteristic of interest is the weight of the filled cans. The lower specification
limit for weight is 2.95 pounds. The table below provides the range and mean of the weights of five
cans tested every fifteen minutes during a day's production. $\begin{array}{|r|r|r||r|r|r|}\hline {\text { Number }} & {\text { XBar }} &{\text { Range }} & {\text { Number }} & {\text { XBar }} & \text { Range } \\\hline 1 & 3.05072 & 0.0215 & 16 & 3.04646 & 0.073 \\\hline 2 & 3.01228 & 0.087 & 17 & 3.03868 & 0.0696 \\\hline 3 & 3.03558 & 0.0851 & 18 & 3.03338 & 0.0329 \\\hline 4 & 3.01014 & 0.0674 & 19 & 3.03322 & 0.0455 \\\hline 5 & 3.00858 & 0.0983 & 20 & 3.05078 & 0.0215 \\\hline 6 & 3.02704 & 0.0527 & 21 & 3.04808 & 0.0396 \\\hline 7 & 3.04268 & 0.0508 & 22 & 3.05348 & 0.0581 \\\hline 8 & 3.01052 & 0.0791 & 23 & 3.05516 & 0.0682 \\\hline 9 & 3.03464 & 0.0663 & 24 & 3.03426 & 0.0325 \\\hline 10 & 3.02034 & 0.0538 & 25 & 3.0516 & 0.0641 \\\hline 11 & 3.03764 & 0.0584 & 26 & 3.05562 & 0.0809 \\\hline 12 & 3.0409 & 0.0434 & 27 & 3.04402 & 0.0374 \\\hline 13 & 3.0519 & 0.0762 & 28 & 3.06458 & 0.0284 \\\hline 14 & 3.03994 & 0.0833 & 29 & 3.0544 & 0.0738 \\\hline 15 & 3.03788 & 0.0601 & & & \\\hline\end{array}$

-Referring to Scenario 18-9, an R chart is to be constructed for the weight. One way to create the
upper control limit involves multiplying the mean of the sample ranges by $D _ { 4 }$ . For this data set,
the value of $D _ { 4 }$ is ________.