stuck on these problems

places.) You buy a lottery ticket to a lottery that costs $10 per ticket. There are only 100 tickets available to be sold in this lottery. In this lottery there are one $470 prize, two $95 prizes, and four $30 prizes. Find your expected gain or loss. (Round your answer to two decimal $ -2.23 XA university has 14 statistics classes scheduled for its Summer 2013 term. One class has space available for 20 students, eight classes have space for 60 students, one class has space for 80 students, and four classes have space for 100 students. (a) what is the average class size assuming each class is filled to capacity? (Enter your answer as a whole number.) 70 students (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. (Enter your answers as fractions.) X P(X = X) X . P(X = x) 20 1/14 1250/7 X 60 8/14 80 1/14 100 4/14 (c) Find the mean of X. (Enter your answer as a whole number.) 70 students (d) Find the standard deviation of X. (Round your answer to two decimal places.) 22 36 students