1. According to WHO (World Health Organization), the mean weight of 12 month old boys is about 9.65 kg and the standard deviation is about 0.87 kg. Use the normal approximation to estimate the given probability. Be sure to justify all steps. (15 points, 5 points each) (1a) The probability that a randomly selected 12 month old boy weighs less than 9 kg. (1b) The probability that a randomly selected 12 month old boy weighs lees than 10 kg. (1c) The probability that the boy's weight is between 9 kg and 10 kg. 90 9.65 10,0