A

waiter

believes the distribution of

his

tips has a model that is slightly skewed to the

left

,

with a mean of

$8.6

0

and a standard deviation of

$6.6

0.

He

usually waits on about

50

parties over a weekend of work.

a) Estimate the probability that

he

will earn at least

$500

.

b) How much does

he

earn on the best

1

%

of such weekends?