Question: A waitperson believes the distribution of tips has a model that is slightly skewed to the right, with a mean of $9.50 and a standard deviation of $5.30. The waitperson usually waits on about 35 parties over a weekend of work.

a) Estimate the probability that the waitperson will earn at least $400 in tips.

b) Determine how much the waitperson earns on their best 15% of such weekends.

c) Determine how much the waitperson earns on their worst 25% of such weekends.