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2.4 Statistical Distributions

2.4 Statistical Distributions

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Question 17

In a game, each person throws a ball into a bucket. For each person, the random variable X X\,X represents the number of times the ball lands in the bucket in the first 5 throws. Helen models X X\,X as X∼B(5,0.3)X \sim B(5, 0.3)X∼B(5,0.3).

a.

State an assumption Helen makes in order to use her model.

[1]
b.

Using Helen's model, find P(X=2)P(X = 2)P(X=2).

[2]
c.

For each person, the random variable Y Y\,Y represents the number of the throw on which the ball first lands in the bucket. Using Helen's model, find P(Y=5)P(Y = 5)P(Y=5).

[2]
Markscheme

2.4 Statistical Distributions Questions

  1. A Level
  2. /Maths
  3. /2.4 Statistical Distributions

390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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