Answer the three questions and show your work on Excel

Below is the factor worksheet

Problem \#3 (30 pts) Bag clips are manufactured at Keep it Fresh. The clip material is first molded and then trimmed to the required shape. The time it takes for the plastic to cool (cure times) during the molding process affects the quality of the bag clips. The aim is to control the cure times statistically using X and R-charts. Cure time data of 36 samples, each of size four, is shown in the Excel file, Problem-3 worksheet. The first 24 samples were taken in April and May, and the last 12 were taken in June. This process is new, so the process standard deviation is not available. Questions 3.1 Prepare X and R-charts using these data with the standard 3-sigma control limit constants A2, D3, and D4 (see the Factors worksheet). (10 points) 3.2 Analyze the charts and comment on whether the process appears to be in control and stable. If the control chart is not in control identify which point(s) are out of control. (10 points) 3.3 Is there any change in the process variation (e.g., the presence of random and assignable variation) from April through June? Briefly explain your observations. If there is a change in the process variation, what approach would you take to address it? (10 points) \begin{tabular}{|rrrrrr|} \hline Sample No. & \multicolumn{5}{c|}{ Observations } \\ \hline 1 & 27.34667 & 27.50085 & 29.94412 & 28.21249 \\ \hline 2 & 27.79695 & 26.15006 & 31.21295 & 31.33272 \\ \hline 3 & 33.53255 & 29.32971 & 29.7046 & 31.053 \\ \hline 4 & 37.98409 & 32.26942 & 31.91741 & 29.44279 \\ \hline 5 & 33.82722 & 30.32543 & 28.38117 & 33.70124 \\ \hline 6 & 29.68356 & 29.56677 & 27.23077 & 34.00417 \\ \hline 7 & 32.6264 & 26.3203 & 32.07892 & 36.17198 \\ \hline 8 & 30.29575 & 30.52868 & 24.43315 & 26.85241 \\ \hline 9 & 28.43856 & 30.48251 & 32.43083 & 30.76162 \\ \hline 10 & 28.2779 & 33.94916 & 30.47406 & 28.87447 \\ \hline 11 & 26.91885 & 27.66133 & 31.46936 & 29.66928 \\ \hline 12 & 28.46547 & 28.29937 & 28.99441 & 31.14511 \\ \hline 13 & 28.84273 & 30.51801 & 32.23614 & 30.47104 \\ \hline 14 & 30.75136 & 32.99922 & 28.08452 & 26.19981 \\ \hline 15 & 31.25754 & 24.29473 & 35.46477 & 28.41126 \\ \hline 16 & 31.24921 & 28.57954 & 35.00865 & 31.23591 \\ \hline 17 & 31.41554 & 35.80049 & 33.60909 & 27.82131 \\ \hline 18 & 32.2023 & 32.02005 & 32.71018 & 29.3762 \\ \hline 19 & 26.91603 & 29.77775 & 33.92696 & 33.78366 \\ \hline 20 & 35.05322 & 32.93284 & 31.51641 & 27.73615 \\ \hline 21 & 32.12483 & 29.32853 & 30.99709 & 31.39641 \\ \hline 22 & 30.09172 & 32.43938 & 27.84725 & 30.70726 \\ \hline 23 & 30.04835 & 27.23709 & 22.01801 & 28.69624 \\ \hline 24 & 29.30273 & 30.83735 & 30.82735 & 31.90733 \\ \hline 25 & 31.6583 & 29.7833 & 31.8791 & 33.9125 \\ \hline 26 & 34.4643 & 25.1848 & 37.76689 & 39.21143 \\ \hline 27 & 41.34268 & 39.5459 & 29.5571 & 32.5735 \\ \hline 28 & 29.4731 & 25.3784 & 25.0438 & 24.0035 \\ \hline 29 & 25.4671 & 34.8516 & 30.1915 & 31.6222 \\ \hline 30 & 46.25184 & 34.71356 & 41.41277 & 44.63319 \\ \hline 31 & 35.4475 & 38.83289 & 33.0886 & 31.6349 \\ \hline 32 & 34.55143 & 33.8633 & 35.18869 & 42.31515 \\ \hline 33 & 43.43549 & 37.36371 & 38.85718 & 39.25132 \\ \hline 34 & 37.05298 & 42.47056 & 35.90282 & 38.21905 \\ \hline 35 & 38.57292 & 39.06772 & 32.2209 & 33.202 \\ \hline 36 & 27.0305 & 33.6397 & 26.6306 & 42.79176 \\ \hline \end{tabular}