Quelpr
1 markRandom Variables

CAPE Applied Mathematics Unit 1 · 2016 · Paper 2 · Question 4(c)(iii)

A discrete random variable X has values 1, 2, 4, 8, 16 with respective probabilities 0.2, 0.1, 0.3, 0.3, 0.1.

Evaluate P(X ≥ 4).

This question uses a figure or table from the paper — you'll see it when you practise.

The mark scheme is shown once you've answered.

Practise this question

Other parts of this question

  1. 4(a)(i)State, with reason, whether or not the given table represents a valid probability distribution.[2 marks]
  2. 4(a)(ii)State, with reason, whether or not the given table represents a valid probability distribution.[2 marks]
  3. 4(a)(iii)State, with reason, whether or not the given table represents a valid probability distribution.[2 marks]
  4. 4(b)(i)Show that k = 1/7.[2 marks]
  5. 4(b)(ii)Determine P(4 ≤ X ≤ 6).[3 marks]
  6. 4(c)(i)Calculate Var(X).[6 marks]
  7. 4(c)(ii)Construct a cumulative distribution table for the random variable X.[2 marks]
  8. 4(d)(i)If 80 persons are introduced to the product, determine the number of persons who are expected to buy the product.[2 marks]
  9. 4(d)(ii)From a random sample of 15 persons who were introduced to the product, calculate the probability that exactly 9 will buy the product.[3 marks]

More practice: the rest of this paper · more Random Variables questions · all CAPE Applied Mathematics Unit 1 past papers