Researchers were interested in the effect of prenatal care on the birth weight of babies. Mothers were divided into two groups, and their babies' weights were recorded in ounces and given below. Mothers in group 1 had recieved five or fewer prenatal visits, and mothers in group 2 had recieved six or more prenatal visits. Group 1: 49, 108, 110, 82, 93, 114, 134, 114, 96, 52, 101, 114 Group 2: 133, 108, 93, 119, 119, 98, 106, 87, 153, 116, 129, 97, 110, 131 Assume that the birth weights of babies of mothers recieving both categories of prenatal care are normally distributed and have the same population variance; denote their respective distributions by N(41, oi) and N(42, 02) with oi = 02. Construct a 95% confidence interval for H1 - 42, the difference in the average birth weights of babies between the mothers who receive less ( < or =5) prenatal visits and the mothers who receive more (> or = 6) prenatal visits. Is there really a difference?