An appliance dealer sells three different models of upright freezers having 13.5, 15.9, and 19.1 cubic feet of storage space, respectively. Let X = the amount of storage space purchased by the next customer to buy a freezer. Suppose that X has the following pmf. x 13.5 15.9 19.1
p(x) 0.20 0.59 0.21

Requried:
a. Compute E(X), E(X2), and V(X).
b. If the price of a freezer having capacity X cubic feet is 22X ? What is the expected price paid by the next customer to buy a freezer?
c. What is the variance of the price paid by the next customer?

What signals you that factoring by grouping is the best method to use when factoring a problem?

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

Find an equation of the line perpendicular to the graph of 28x-7y=9 that passes through the point at (4,1)