Question 2 A new method of packaging for a drug, making use of hermetically sealed capsules containing an oxygen-free gas mixture is being developed, to try to extend the shelf life of a preparation with a nominal potency of 10 mg which is degraded by atmospheric oxygen. Samples of five are assayed after 2, 4, 6, 8, 10 and 12 months from a batch stored under standard conditions, and from another batch stored under the new conditions. The results are given below. Months Std(mg) New(mg) Months Std(mg) New (mg) 22222 9 9 9 10 10 10 10 9 8 2 10 9 0 00 00 00 00 8 8 8 8 8 9 8 8 8 10 9 8 8 8 4 8 10 10 4 9 9 10 4 10 9 10 4 9 9 10 4 10 10 10 8 10 12 6 9 10 12 6 9 9 12 6 8 9 12 6 8 9 12 77888 8 8 8 7 8 9 8 9 8 Compute linear regression lines of potency on time elapsed for each of the two prepa- rations. For the new storgage conditions, comment on the model fit in terms of the coefficient of determination and the residual plots.