A museum offers several levels of membership, as shown in the table.

a) Find the mean and standard deviation of the donations.
b) During their annual membership drive, they hope to sign up 50 new members each day. Would you expect the distribution of the donations for a day to follow a Normal model? Explain.
c) Consider the mean donation of the 50 new members each day. Describe the sampling model for these means (shape, center, and spread).