Quiz on Random Variables and Expectation

Which of the following is a type of random variable?

• Integer

• Continuous

• Real number

• Imaginary

A random variable that can take only a finite or countably infinite number of values is called:

• Continuous random variable

• Discrete random variable

• Gaussian variable

• Fixed variable

The probability distribution of a continuous random variable is defined using:

• Probability mass function

• Probability density function

• Cumulative function

• Expectation function

Which function gives the probability that a random variable is less than or equal to a certain value?

• Density function

• Distribution function

• Expectation function

• Mass function

The expected value of a constant is:

• Zero

• One

• The constant itself

• Undefined

The expectation of a discrete random variable X is given by:

• ∑P(X)

• ∑xP(x)

• ∑x²P(x)

• ∑x

The expectation of X² is used to compute:

• Mean

• Median

• Variance

• Mode

If X is a random variable and a, b are constants, then E(aX + b) =

• a E(X) + b

• E(X) + ab

• ab E(X)

• a + b E(X)

Which of the following is a property of expectation?

• E(X + Y) = E(X) + E(Y)

• E(XY) = E(X) + E(Y)

• E(X - Y) = E(X) × E(Y)

• E(XY) = E(X) / E(Y)

The variance of a random variable X is defined as:

• E(X²)

• [E(X)]²

• E(X²) - [E(X)]²

• √E(X)