A clothing store asserts that 60% of its customers pay by credit. On a particular day, 35 customers purchased items at the store. a. What is the mean and standard deviation of the binomial distribution? b. What is the probability that half (18 or more) of the customers paid by credit? c. What is the probability that 30 or more paid by credit? d. What is the probability that less than 12 paid by credit? e. What is the probability that 12 to 30 paid by credit?