On the planet of mercury, 4-year-olds average 3.2 hours a day unsupervised. most of the unsupervised children live in rural areas, considered safe. suppose that the standard deviation is 1.6 hours and the amount of time spent alone is normally distributed. we randomly survey one mercurian 4-year-old living in a rural area. we are interested in the amount of time x the child spends alone per day. (source: san jose mercury news) round all answers to 4 decimal places where possible. a. what is the distribution of x?