3. For each day that Sasha travels to work, the probability that she will experience a delay due to
traffic is 0.2. Each day can be considered independent of the other days.
(a) For the next 21 days that Sasha travels to work, what is the probability that Sasha will
experience a delay due to traffic on at least 3 of the days?
(b) What is the probability that Sasha’s first delay due to traffic will occur after the fifth day of
travel to work?

(c) Consider a random sample of 21 days that Sasha will travel to work. For the proportion of
those days that she will experience a delay due to traffic, is the sampling distribution of the
sample proportion approximately normal? Justify your answer