TABLE 18-9
the Manufacturer of Cat Food Constructed Control

TABLE 18-9
The manufacturer of cat 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.
$\begin{array}{cclccc}\text { Number } & \text { XBar } & \text { Range } & \text { Number } & \text { XBar } & \text { Range } \\\hline 1 & 3.05072 & 0.0215 & 16 & 3.04646 & 0.073 \\2 & 3.01228 & 0.087 & 17 & 3.03868 & 0.0696 \\3 & 3.03558 & 0.0851 & 18 & 3.03338 & 0.0329 \\4 & 3.01014 & 0.0674 & 19 & 3.03322 & 0.0455 \\5 & 3.00858 & 0.0983 & 20 & 3.05078 & 0.0215 \\6 & 3.02704 & 0.0527 & 21 & 3.04808 & 0.0396 \\7 & 3.04268 & 0.0508 & 22 & 3.05348 & 0.0581 \\8 & 3.01052 & 0.0791 & 23 & 3.05516 & 0.0682 \\9 & 3.03464 & 0.0663 & 24 & 3.03426 & 0.0325 \\10 & 3.02034 & 0.0538 & 25 & 3.0516 & 0.0641 \\11 & 3.03764 & 0.0584 & 26 & 3.05562 & 0.0809 \\12 & 3.0409 & 0.0434 & 27 & 3.04402 & 0.0374 \\13 & 3.0519 & 0.0762 & 28 & 3.06458 & 0.0284 \\14 & 3.03994 & 0.0833 & 29 & 3.0544 & 0.0738 \\15 & 3.03788 & 0.0601 & & & \\\hline\end{array}$




-Referring to Table 18-9, an R chart is to be constructed for the weight. The center line of this R chart is located at ______.