Suppose the census bureau reports that the monthly household income for a particular region is normally distributed with mean of $5000 and a standard deviation of $1500.
a. find the probability that a randomly selected household has a monthly income greater than 6800.
b. if we take a sample of 40 households, what is the probability that the sample mean for the monthly income will be greater than$5400?

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."

1. if events a and b are non-overlapping events, how do you find the probability that one or the other occurs? 2. what does it mean if p(a or b) equals 1?

Arectangle has a length of 6cm by 8cm what is the length of a diagonal of the rectangle