1. We toss a coin three times. Let X be the number of heads we observe. (a) Find the probability distribution of X. (b) Calculate the mean of X (i.e. px).2. A clothing store has determined that 30% of the people who enter the store will make a purchase. Eight people enter the store during a one-hour period. (a) Find the probability that exactly four people will make a purchase. (b) Find the probability that less than three people will make a purchase