Free Probability Distributions MCQs with Answers

132 Probability Distributions MCQs from Statistics, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.

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132 questions · page 7 of 7

  • A. 1
  • B. 2
  • C. 0
  • D. Constant

Explanation: For a continuous random variable, probability is assigned to intervals, not individual points, so P(X = x) = 0.

Correct answer: 0
  • A. P(X=x)
  • B. P(X
  • C. P(X>x)
  • D. P(X≤x)

Explanation: The distribution function is the cumulative probability up to and including x, written F(x)=P(X≤x).

Correct answer: P(X≤x)
  • A. Negative
  • B. Non Negative
  • C. Positive
  • D. None

Explanation: A probability function cannot assign a negative value, so it is non-negative for every possible outcome.

Correct answer: Non Negative
  • A. A Table
  • B. A Graph
  • C. A mathematical Equation
  • D. All of these

Explanation: A discrete probability distribution can be listed in a table, displayed graphically, or expressed through a mathematical formula.

Correct answer: All of these
  • A. ∑P(x)
  • B. ∑x.P(x)
  • C. ∑x2P(x)
  • D. One

Explanation: For a discrete random variable, expected value is obtained by multiplying each value by its probability and summing: E(X)=∑xP(x).

Correct answer: ∑x.P(x)
  • A. Var(bX) + a
  • B. b2 Var(X)
  • C. b Var(x)
  • D. None of these

Explanation: Adding a constant does not change variance, while multiplying a variable by b multiplies its variance by b². Thus Var(a+bX)=b²Var(X).

Correct answer: b2 Var(X)
  • A. Not a function
  • B. A continuous variable
  • C. A function
  • D. None of these

Explanation: A random variable is a function that assigns a real number to each outcome in the sample space.

Correct answer: A function
  • A. Random function
  • B. Distribution function
  • C. Continuous function
  • D. probability function

Explanation: The distribution function, or cumulative distribution function, gives the probability that X is less than or equal to a specified value…

Correct answer: Distribution function
  • A. fixed
  • B. continuous
  • C. discrete
  • D. discrete or continuous

Explanation: A random variable can have countable outcomes, making it discrete, or values over an interval, making it continuous.

Correct answer: discrete or continuous
  • A. E(x) - E(x)
  • B. E(X) - 0
  • C. 0
  • D. E(x) + E(x)

Explanation: Using the linearity of expectation, E[X − E(X)] = E(X) − E(X) = 0. Subtracting a random variable's own mean produces a deviation whose…

Correct answer: 0
  • A. Discrete
  • B. Variable
  • C. Scale
  • D. Non of these

Explanation: A discrete random variable is defined on a discrete sample space, whose outcomes can be listed or counted.

Correct answer: Discrete
  • A. a discrete variable
  • B. a continuous variable
  • C. a constant
  • D. a qualitative variable

Explanation: The sum of two dice can take only the integer values 2 through 12, giving a finite set of possible outcomes.

Correct answer: a discrete variable