please answer question 18 and 19 and 20

QUESTION 18 In a department store there are 186 customers, 57 of whome will buy at least one item. If 4 customers are selected at random, find the probability that all will buy at least one item. Round your answer to four decimal places. QUESTION 19 Statistics Canada reports that 27.97% of all deaths are attributable to heart disease. Find the mean for the number of such deaths that will occur in a typical region with 3,002 deaths. Round your answer to two decimal places. QUESTION 20 A factory manager collected data on the number of equipement breakdowns per day. From those data, she derived the probability distribution shown in the table below. X 0 1 2 P(X=x) 0.75 0.15 0.1 Find the mean and standard deviation of the number of of equipement breakdowns per day. Round your answer to two decimal places