Suppose x and y are random variables with joint density function. f(x, y) = 0.1e−(0.5x + 0.2y) if x ≥ 0, y ≥ 0 0 otherwise (a) is f a joint density function? yes no (b) find p(y ≥ 8). (round your answer to four decimal places.) find p(x ≤ 5, y ≤ 8). (round your answer to four decimal places.) (c) find the expected value of x. find the expected value of y.

State if the two triangles are congruent. if they are, state how you know?

Solve the problem. a student earned grades of c, a, b, and a in four different courses. those courses had these corresponding numbers of credit hours: 4, 5, 1, and 5. the grading system assigns quality points to letter grades as follows: a = 4, b = 3, c = 2, d = 1, and f = 0. compute the grade point average (gpa) and round the result to two decimal places. 3.40 3.50 8.75 2.18

3x + 4y = 5 x- 3y = -7 solve by substitution