Random and independent samples of 85 recent prime time airings from each of two major networks have been considered. The first network aired a mean of 109.2 commercials during prime time, with a standard deviation of 5.5 commercials. The second network aired a mean of 110.8 commercials, with a standard deviation of 5.4 commercials. As the sample sizes are quite large, the population standard deviations can be estimated using the sample standard deviations. Construct a 95% confidence interval for 1-2, the difference between the mean number of commercials 1 aired during prime time by the first network and the mean number of commercials 2 aired during prime time by the second network.