The national average cost per student for books and supplies at four-year private colleges in 2011–2012 was $1,213. Assume the same average is true for the upcoming school year and these expenses are approximately normally distributed, with a standard deviation of $68.
a. What percentage of students will have expenses for books and supplies between $1100 and $1150?
b. What percentage of students will have expenses for books and supplies less than $1350?
c. If a student budgets $1250 for books and supplies, there’s a _____% probability that he/she will end up at least $50 short.
d. To ensure no more than a 1% chance of being short, a student should budget $_____ for books and supplies.