Assume that​ women's heights are normally distributed with a mean given by mu equals 63.4 in​, and a standard deviation given by sigma equals 2.4 in. ​(a) if 1 woman is randomly​ selected, find the probability that her height is less than 64 in. ​(b) if 44 women are randomly​ selected, find the probability that they have a mean height less than 64 in.