Suppose you are playing a game.

Question

Suppose you are playing a game. The random variable, Y, represents your net profit in dollars. The probability

distribution of Y is as follows. (Round your answers to 4 decimal places, if needed.)

y -3 -2 1 3 5

P(Y=y) 0.15 0.13 ? 0.18 0.2

(a) What is the mean for net profit?

(b) What is the median for net profit?

(c) What is the standard deviation for net profit?

Answer 1

P(Y = 1) will equal 1 - P(y = -3 or -2 or 3 or 5)

mean is sum of (y * P(Y = y)) y - -3, -2, 1, 3 and 5

median is y value where cumulative frequency is 0.5

variance = sum [(y^2 * P(Y=y)] - mean^2

standard deviation is the square root of the variance