I need Assistance in these three problems please

5.Florida State University has 14 statistics classes scheduled for its Summer 2013 term. One class has space available for 30 students, eight classes have space for 60 students, one class has space for 70 students, and four classes have space for 100 students.

a.What is the average class size assuming each class is filled to capacity?

b.Space is available for 980 students. Suppose that each class is filled to capacity and select a statistics student at random. Let the random variable X equal the size of the student's class. Define the PDF for X.

c.Find the mean of X.

d.Find the standard deviation of X.

7.According to a study by Dr. John McDougall of his live-in weight loss program, the people who follow his program lose between 6 and 15 pounds a month until they approach trim body weight. Let's suppose that the weight loss is uniformly distributed. We are interested in the weight loss of a randomly selected individual following the program for one month.

a.Define the random variable. X = _________

b.X ~ _________

c.Graph the probability distribution.

d.f(x) = _________

e. = _________

f. = _________

8.The percent of persons (ages 5 and older) in each state who speak a language at home other than English is approximately exponentially distributed with a mean of 9.848. Suppose we randomly pick a state.

a.Define the random variable. X = _________________________________.

b.Is X continuous or discrete?

c.X ~ ________

d. = ________

e. = ________