TABLE 17-9
the Manufacturer of Canned Food Constructed Control Charts

TABLE 17-9
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.
$\begin{array}{|r|r|r|r|r|r|}\hline Number&XBar&Rang&Number&XBar&Range\\\hline 1 & 3.05072 & 0.0215 & 1 & 3.04646 & 0.073 \\\hline 3 & 3.01228 & 0.087 & 17 & 3.03868 & 0.0696 \\\hline 3 & 3.03558 & 0.0851 & 19 & 3.03338 & 0.0329 \\\hline 4 & 3.01014 & 0.0674 & 19 & 3.03322 & 0.0455 \\\hline 5 & 3.00858 & 0.0983 & 29 & 3.05078 & 0.0215 \\\hline 9 & 3.02704 & 0.0527 & 21 & 3.04808 & 0.0396 \\\hline 7 & 3.04268 & 0.0508 & 23 & 3.05348 & 0.0581 \\\hline 9 & 3.01052 & 0.0791 & 23 & 3.05516 & 0.0682 \\\hline 9 & 3.03464 & 0.0663 & 24 & 3.03426 & 0.0325 \\\hline 19 & 3.02034 & 0.0538 & 25 & 3.0516 & 0.064 \\\hline 11 & 3.03764 & 0.0584 & 29 & 3.05562 & 0.0809 \\\hline 12 & 3.0409 & 0.0434 & 27 & 3.04402 & 0.0374 \\\hline 13 & 3.0519 & 0.0762 & 29 & 3.06458 & 0.0284 \\\hline 14 & 3.03994 & 0.0833 & 29 & 3.0544 & 0.0738\\\hline15 & 3.03788 & 0.0601\\\hline\end{array}$
-Referring to Table 17-9, an $\bar { X }$ chart is to be used for the weight. One way to obtain the control limits is to take the grand mean and add and subtract the product of A₂ times the mean of the sample ranges. For this data set, the value of A₂ is ________.