Edexcel S2 2015 June — Question 7 7 marks

Exam BoardEdexcel
ModuleS2 (Statistics 2)
Year2015
SessionJune
Marks7
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Mark schemeDownload PDF ↗
TopicDiscrete Random Variables
TypeSampling distribution of median
DifficultyStandard +0.8 This question requires understanding of sampling distributions and medians, systematic enumeration of all possible samples with their probabilities (considering the given ratio), and careful identification of the median in each case. It's more conceptually demanding than routine S2 questions and requires organized multi-step reasoning, but remains within standard A-level scope without requiring novel insight.
Spec5.02a Discrete probability distributions: general

A bag contains a large number of 10p, 20p and 50p coins in the ratio 1 : 2 : 2 A random sample of 3 coins is taken from the bag. Find the sampling distribution of the median of these samples. [7]

A bag contains a large number of 10p, 20p and 50p coins in the ratio 1 : 2 : 2

A random sample of 3 coins is taken from the bag.

Find the sampling distribution of the median of these samples. [7]

\hfill \mbox{\textit{Edexcel S2 2015 Q7 [7]}}