1. The arithmetic mean of all possible outcomes is known as
(A) expected value
(B) critical value
(C) variance
(D) standard deviation

Expectation (or expected value) is the arithmetic mean of all possible outcomes of a random variable.

2. Which of the following cannot be the value of a correlation coefficient?
(A) –1
(B) –0.75
(C) 0
(D) 1.2

The value of a correlation coefficient is always between –1 and 1, including –1 and 1.

3. Var (X) = ?
(A) E[X2] (B) E[X2] – E[X] (C) E[X2] + E[X]2
(D) E[X2] – E[X]2

By definition, Var (X) = E[X2] – E[X]2

4. Var (X + Y) = ?
(A) E[X/Y] + E[Y] (B) E[Y/X] + E[X] (C) Var(X) + Var(Y) + 2 Cov(X, Y)
(D) Var(X) + Var(Y) – 2 Cov(X, Y)

By definition, Var (X + Y) = Var(X) + Var(Y) + 2 Cov(X, Y)

5. What is the variance of the data set: 2, 10, 1, 9, and 3?
(A) 15.5
(B) 17.5
(C) 5.5
(D) 7.5

First, calculate the mean Now calculate the variance, ENGLISH

1. Tunde and Tania went shopping, but __________ couldn’t find anything __________ liked.
(A) they, those
(B) they, them
(C) those, they
(D) they, they

2. Nuclear energy is __________ dangerous to be used widely.
(A) so
(B) such
(C) too
(D) that

3. If I have money, I __________ it tomorrow.
(A) will purchase
(B) would purchase
(C) have purchase
(D) have purchased

4. Cannon had __________ unique qualities _________ it was used widely in ancient times.
(A) such, that
(B) such, so
(C) that, since
(D) that, that

GENERAL

1. The oldest news agency in the world is
(A) AFP
(B) WAFA
(C) BBC
(D) CNN

2. AFP is a renowned news agency of which country?
(A) Switzerland
(B) France
(C) Germany
(D) Sweden

3. How many electoral votes are required in the US presidential elections to become president of the United States?
(A) 250
(B) 270
(C) 350
(D) 370

4. Currently, the largest economy in the world is the economy of
(A) China
(B) Russia
(C) Germany
(D) United States