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4.2 Statistical distributions (A-level only)

4.2 Statistical distributions (A-level only)

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Question 128

In a large residential district, it is estimated that 22% of households have installed solar panels.

a.

State two assumptions required to model the number of households with solar panels in a random sample of size nnn using a binomial distribution.

[2]
b.

Using this model, find the probability that exactly 4 households have solar panels in a random sample of 18 households.

[2]
c.

Calculate the mean and the variance of the number of households with solar panels in a random sample of 250 households.

[2]
d.

A regional council inspects a random sample of 250 households. The district is classified as 'Eco-Leading' if more than 62 households in the sample have installed solar panels.

Using a suitable approximation, find the probability that the district will be classified as 'Eco-Leading'.

[4]
Markscheme

4.2 Statistical distributions (A-level only) Questions

  1. A Level
  2. /Maths
  3. /4.2 Statistical distributions (A-level only)

328 exam-style questions on WJEC A Level Maths 4.2 Statistical distributions (A-level only), covering 4.2.1 Statistical distributions (A-level only), 4.2.2 Statistical distributions (A-level only), and 4.2.3 Statistical distributions (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

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