Mathematics 9709/72 — October/November 2017

Cambridge A-Level · Probability & Statistics 2 · worked solutions for every part, with the mark scheme

questions

marks

minutes

Topics The Poisson Distribution · Linear Combinations of Random Variables · Sampling and Estimation · Hypothesis Tests · Continuous Random Variables

Q1The Poisson DistributionLinear Combinations of Random VariablesFree sample

(a)

(i)

A random variable $X$ has the distribution $B(2540, 0.001)$ . Use the Poisson approximation to the binomial distribution to find $P(X > 1)$ .

(ii)

Explain why the Poisson approximation is appropriate in this case.

(b)

Two independent random variables, $S$ and $T$ , have distributions $Po(2.1)$ and $Po(3.5)$ respectively. Find the mean and standard deviation of $S + T$ .

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5 more questions

Q2Sampling and Estimation6M
Q3Hypothesis Tests · Sampling and Estimation8M
Q4Continuous Random Variables10M
Q5Linear Combinations of Random Variables10M
Q6The Poisson Distribution · Hypothesis Tests10M

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