Assume that women's weights are normally distributed with a mean given by $\mu=143$ lb and a standard deviation given by $\sigma=29$ lb.
(a) If 1 woman is randomly selected, find the probabity that her weight is below $108$

(b) If $3$ women are randomly selected, find the probability that they have a mean weight below $108$

(c) If $79$ women are randomly selected, find the probability that they have a mean weight below $108$