# MCQs Random Variables 2

1. If $X$ and $Y$ are independent random variables then $VAR(X-Y)$ is equal to

2. For a continuous random variable $X$, the total probability of the mutually exclusive events (intervals) within which $X$ can assume a value is

3. $Var(X/3)=$?

4. The probability that a continuous random variable assumes a single value is

5. $Var(X+4)=$?

6. If $Var(X) = 4$ then $Var(3X+5)$ is equal to

7. If $X$ and $Y$ are independent random variables then $E(XY)$ is equal to

8. A continuous random variable is a random variable that can

9. If $X$ is a random variables, $a$ and $b$ are constants then $E(aX+b)$ is equal to

10. If $X$ and $Y$ are independent then $Var(X-Y)$ is

11. If $X$ is a random varaible, then $Var(2-3X)$ is

12. $Var(2X+5) =$ ?

13. If $SD(X) = 3$ then $SD(X+4/6)$ is

14. $Var(3X – 4Y)=$?

15. For a continuous random variable, the area under the probability distribution curve between any two points is always

A Random Variable (random quantity or stochastic variable) is a set of possible values from a random experiment.

The domain of a random variable is called sample space. For example, in the case of a coin toss experiment, there are only two possible outcomes, namely heads or tails. A random variable can be either discrete or continuous. The discrete random variable takes only certain values such as 1, 2, 3, etc., and a continuous random variable can take any value within a range such as the height of persons.