A waiter believes the distribution of his tips has a model that is slightly skewed to the right, with a mean of $10.10 and a standard deviation of $6.50. He usually waits on about 40 parties over a weekend of work. a) Estimate the probability that he will earn at least $450. b) How much does he earn on the best 10% of such weekends? . . . . . a) P(tips from 40 parties > $450) = (Round to four decimal places as needed.) b) The total amount that he earns on the best 10% of such weekends is at least $ (Round to two decimal places as needed.)