Quelpr
3 marksSampling Distribution and Estimation

CAPE Applied Mathematics Unit 1 · 2015 · Paper 2 · Question 5(b)(i)

Random variable X has E[X] = 25 and Var[X] = 144. Samples of size 81 are taken from X.

State the approximate distribution modelled by X̄, giving its parameters.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 5(a)(i)Calculate the width of the interval.[2 marks]
  2. 5(a)(ii)Calculate the mean of the sample.[2 marks]
  3. 5(a)(iii)Calculate the standard deviation of the value of the sales invoice.[3 marks]
  4. 5(b)(ii)Calculate P(X̄ < 28).[5 marks]
  5. 5(c)(i)State null and alternative hypotheses, using statistical symbols to test whether the mean mass has changed.[2 marks]
  6. 5(c)(ii)Determine the critical region(s) of the test conducted at the 4% significance level.[3 marks]
  7. 5(c)(iii)Calculate the value of the test statistic used in this test.[3 marks]
  8. 5(c)(iv)Clearly state the conclusion of the test.[2 marks]

More practice: the rest of this paper · more Sampling Distribution and Estimation questions · all CAPE Applied Mathematics Unit 1 past papers