Psychologists estimate that 80% of male drivers, when lost in trying to find a location, continue to drive rather than asking directions.

Psychologists estimate that 80% of male drivers, when lost in trying to find a location, continue to drive rather than asking directions. If this estimate is correct, what is the probability that, in a random sample of 100 lost male drivers, the proportion who continue to drive is

a.) at least 0.70?

b.) less than 0.85?