Let x, y , z be three random variables which satisfy the following conditions: var(x) = 4, var(y ) = 9, var(z) = 16. cov(x, y ) = −2, cov(z, x) = 3, and y and z are independent. find: (a) cov(x + 2y, y − z). (b) var(3x − y ). (c) var(x + y + z)

Rewrite 9 log, x2 in a form that does not use exponents. 9log, x = log, x

According to the 2008 u.s. census, california had a population of approximately 4 × 10^7 people and florida had a population of approximately 2 × 10^7 people. which of the following is true? a. the population of california was approximately two times the population of florida. b. the population of florida was approximately twenty times the population of california. c. the population of florida was approximately two times the population of california. d. the population of california was approximately twenty times the population of florida.

C. using a standard deck of 52 cards, the probability of selecting a 4 of diamonds or a 4 of hearts is an example of a mutually exclusive event. true of false