A grocery store's receipts show that Sunday customer purchases have a skewed distribution with a mean of $35 and a standard deviation of $20. Suppose the store had 294 customers this Sunday. a) Estimate the probability that the store's revenues were at least $10,800. b) If, on a typical Sunday, the store serves 294 customers, how much does the store take in on the worst 10% of such days? a) The probability is !]. (Round to four decimal places as needed.) b) The store takes in at most $]. (Round to two decimal places as needed.)