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 11 of 14

101. The hypergeometric probability distribution is used rather than the binomial or Poisson when the sampling is performed ?

Moderate
  • A. With replacement
  • B. With out replacement from an infinite population
  • C. With out replacement from a finite population
  • D. With replacement from a finite population

Explanation: The hypergeometric distribution applies when draws are made without replacement from a finite population, so the success probability changes after each draw. With replacement, trials remain independent and binomial modelling is appropriate.

Correct answer: With out replacement from a finite population

102. When X denotes the number of success in binomial experiment, it is called ________________?

Moderate
  • A. Random variable
  • B. Binomial random variable
  • C. Continuous random variable
  • D. Both (b) and (c) but not (a)

Explanation: The number of successes in a fixed number of binomial trials is specifically called a binomial random variable. It is also a random variable in the general sense, but it is discrete rather than continuous.

Correct answer: Binomial random variable

103. In binomial experiment successive trials are ______________?

Moderate
  • A. Dependent
  • B. Independent
  • C. May be inependent or dependent
  • D. None of these

Explanation: Binomial trials must be independent, meaning the result of one trial does not affect the result of another. This condition, together with a constant success probability and two outcomes, defines the binomial experiment.

Correct answer: Independent

104. In binomial experiment, the successive trials are _____________?

Moderate
  • A. Dependent
  • B. independent
  • C. Related
  • D. constant

Explanation: Successive trials in a binomial experiment are independent, so one trial does not alter the outcome probabilities of the others. “Constant” describes the probability of success, not the relationship between trials.

Correct answer: independent

105. In the binomial experiment, the outcomes of each trial maybe classified into ______________?

Moderate
  • A. Success
  • B. Failure
  • C. Success or Failure
  • D. None of these

Explanation: Each binomial trial has exactly two mutually exclusive outcomes, conventionally labelled success and failure. The labels do not imply that success is favourable or failure is undesirable.

Correct answer: Success or Failure

106. A binomial random variable can assume values from _________ to n?

Moderate
  • A. 6
  • B. 3
  • C. 2
  • D. 0

Explanation: If X counts successes in n trials, it can take every integer value from 0, meaning no successes, through n, meaning success on every trial. Therefore the lower limit is 0.

Correct answer: 0

107. In binomial distribution the probability of success remains __________ from trial to trial?

Moderate
  • A. Constant
  • B. Varies
  • C. Four
  • D. Probability

Explanation: A binomial distribution requires the probability of success, p, to remain constant from one trial to the next. If that probability varies, the standard binomial model no longer applies.

Correct answer: Constant

108. Which of the following is a true statement for comparing the t distribution with standard normal ?

Moderate
  • A. Greater the degree of freedom, the more the t-distribution resembles the standard normal distribution
  • B. The Normal Curve is symmetrical whereas the t-distribution are slightly skewed.
  • C. The proportion of area beyond a specific value of "t" is less than the proportion of normal curve
  • D. Non of these

Explanation: As the degrees of freedom increase, the estimated variance becomes more stable and the t distribution approaches the standard normal distribution. The t distribution has heavier tails for finite degrees of freedom, not lighter tails as option c suggests.

Correct answer: Greater the degree of freedom, the more the t-distribution resembles the standard normal distribution

109. The t distribution are_____________?

Moderate
  • A. Symmetrical
  • B. None of these
  • C. Same as Normal Curve
  • D. Skewed

Explanation: The t distribution is symmetric about zero, like the standard normal distribution, although it has heavier tails for finite degrees of freedom. It is therefore not skewed.

Correct answer: Symmetrical

110. Which of the following is an assumption underlying the use of the t-distribution ?

Moderate
  • A. The sample are drawn from a normally distributed population.
  • B. The variance of the population is known
  • C. All above
  • D. s (sample standard deviation) is an unbiased estimate of the population variance.

Explanation: The usual t procedure assumes that the sample comes from a normally distributed population, especially for small samples. The population variance is unknown, while s², not s itself, is an unbiased estimator of the population variance.

Correct answer: The sample are drawn from a normally distributed population.