Lesson 2.04h

2.04h Selecting a distribution Quiz: OCR Maths, Unit 14

20 questions

Written by Revision Ninja · Last reviewed 11 October 2026

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Lesson 2.04h, Selecting a distribution: 20 multiple choice questions for the OCR Maths (H240), Unit 14: Statistical Distributions, written with Revision Ninja.

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The 20 questions

  1. Which condition is required for a variable to follow a binomial distribution?

    • Symmetrical shape
    • Infinite trials
    • Continuous data
    • Independent trials

  2. For X ~ B(n, p), what is the mean of X?

    • np
    • n(1 - p)
    • np(1 - p)
    • p/n

  3. For X ~ B(n, p), what is the variance of X?

    • np
    • p(1 - p)/n
    • np(1 - p)
    • n(1 - p)^2

  4. What type of data is a normal distribution primarily used to model?

    • Discrete counts
    • Categorical data
    • Continuous data
    • Binary outcomes

  5. Which distribution models the number of successes in fixed independent trials?

    • Binomial
    • Poisson
    • Normal
    • Uniform

  6. Under what main condition can a binomial distribution be approximated by a normal distribution?

    • Small trial count
    • Probability near zero
    • Large trial count
    • Continuous trial outcomes

  7. Why is a normal approximation unsuitable for a binomial variable with n = 4?

    • Trials not independent
    • Trial count too small
    • Probability too high
    • Variance too large

  8. An inspector checks 20 independent items with constant defect probability. Which model applies?

    • Continuous distribution
    • Binomial distribution
    • Normal distribution
    • Uniform distribution

  9. Which probability distribution is most suitable for modelling egg masses from a farm?

    • Discrete uniform distribution
    • Normal distribution
    • Bivariate distribution
    • Binomial distribution

  10. 500 people independently answer yes or no with constant probability. Which model fits total 'yes' answers?

    • Binomial distribution
    • Normal distribution
    • Exponential distribution
    • Uniform distribution

  11. Why is drawing 10 cards without replacement from a deck not strictly binomial?

    • Variable trial count
    • Continuous outcomes
    • Infinite outcomes
    • Non-constant probability

  12. For 1000 independent trials with success probability 0.5, which distribution best approximates the binomial count?

    • Poisson distribution
    • Exponential distribution
    • Uniform distribution
    • Normal distribution

  13. Which binomial condition is violated if the probability of success changes over time?

    • Binary outcomes
    • Fixed trial number
    • Independent trials
    • Constant probability

  14. Which binomial assumption is violated when counting trials until the first success?

    • Constant success probability
    • Fixed trial number
    • Two possible outcomes
    • Independent trials

  15. Which model best fits the discrete count of heads obtained in six coin tosses?

    • Binomial model
    • Continuous model
    • Normal model
    • Uniform model

  16. What is the theoretical variance of a binomial distribution B(n, p)?

    • np
    • n^2 p
    • np(1 - p)
    • sqrt(np)

  17. A researcher models the number of rainy days in a 30-day month with B(30, 0.4). Which statement is correct about the model's mean and variance?

    • Mean 30 and variance 12
    • Mean 0.4 and variance 0.24
    • Mean 12 and variance 12
    • Mean 12 and variance 7.2

  18. Which distribution model best fits a set of continuous human height data?

    • Binomial distribution
    • Normal distribution
    • Discrete distribution
    • Uniform distribution

  19. A student guesses 25 four-option questions. Which binomial model fits their total score?

    • B(4, 0.25)
    • B(25, 0.4)
    • B(25, 0.25)
    • N(25, 0.25)

  20. Which distribution is best suited for modelling the number of emails arriving per hour?

    • Poisson
    • Binomial
    • Uniform
    • Normal

All OCR Maths quizzes