Two causes of poor power quality are “sags” and “swells.” A SAG is an unusual dip and a swell is an unusual increase in the voltage level of a transformer. For transformers built for heavy industry, the main number of swirls per week was 184 with a standard deviation of 28.4 swirls per week. The main number of sags her week was 326 With a standard deviation of 33 sacks per week. Assume that both the number of sags and the number of swirls are normally distributed. Suppose one of the Transformers is randomly selected and found to have 420 sags in 70 sags in a week.

a. What is the probability that the number of sex per week is less than 420?
b. What is the probability that the number of swirls per week is greater than 70?