The expected value of the sum of two random variables X and Y is equal to the ____________________ of the expected value of X and the expected value of Y.
Fill in the blank(s) with correct word
Q. 2The ____________________ of X and Y is a measure of the strength and direction of the linear relationship between X and Y. It is easy to put into perspective because it is always between -1 and 1.
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Q. 3The ____________________ of X and Y is one measure of the strength and direction of the linear relationship between X and Y. However this number is hard to put into perspective.
Fill in the blank(s) with correct word
Q. 4A(n) ____________________ distribution provides probabilities of combinations of two random variables.
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Q. 5If X and Y are independent random variables, which of the following identities is false?
a. COV(X, Y) = 1
b. E(X + Y) = E(X) + E(Y)
c. V(X + Y) = V(X) + V(Y)
d. All of these choices are true.
Q. 6If X and Y are any random variables with E(X) = 5, E(Y) = 6, E(XY) = 21, V(X) = 9 and V(Y) = 10, then the relationship between X and Y is a:
a. strong positive relationship
b. strong negative relationship
c. weak positive relationship
d. weak negative relationship
Q. 7The covariance of two variables X and Y:
a. must be between -1 and +1.
b. must be positive.
c. can be any real number.
d. None of these choices.
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