An experiment was done in the study Doksum and Sievers (1976) to measure the effects of ozone, a component of smog. A group of 22 70-day-old rats were kept in an environment containing ozone for 7 days, and their weight gains were recorded. Another group of 23 rats of a similar age were kept in an ozone-free environment for a similar time, and their weight gains were recorded. The data (in grams) are given below. Controls Ozone 41.0 38.4 24.9 10.1 6.1 20.4 25.9 21.9 18.3 7.3 14.3 15.5 13.1 27.3 28.5 -9.9 6.8 28.2 -16.9 17.4 21.8 17.9 -12.9 14.0 15.4 27.4 19.2 6.6 12.1 15.7 22.4 17.7 26.0 39.9 -15.9 54.6 29.4 21.4 22.7 -14.7 44.1 -9.0 26.0 26.6 -9.0 Let c and to be the means of the two groups. Write an R program and find the 95% confidence interval for the difference uc - Ho under the Normal samples-assumption.