From past experience, a server at a restaurant knows that her tips follow a right-skewed distribution with mean $6 and standard deviation $4.
What is the probability that the servers next 30 tips have a mean between $6 and $7? ( Assume that these 30 customers represent a simple random sample).
If the server has 40 customers in one shift, what is the probability that her total tips are less than $250? ( Assume that these 40 customers represent a simple random sample).