Skip to content

Course home

2.4 Statistical Distributions

2.4 Statistical Distributions

EasyMediumHard
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172
Question 9

Applicants for a specialized coding bootcamp are screened for a specific learning aptitude. Historical data shows that the proportion of applicants identified as having this rare aptitude is 0.032.

a.

Write down a suitable model for the distribution of the number of applicants identified with this aptitude from a total of nnn applicants.

[1]
b.

State one assumption necessary for this distribution to be a suitable model of this situation.

[1]
c.

Using a suitable approximation, find the probability that exactly 4 out of 150 applicants are identified as having this aptitude.

[3]
d.

Explain why the approximation that you used in part (c) is appropriate.

[1]
e.

An instructor claims that 80% of all accepted applicants successfully complete the advanced certification.

From a random sample of 120 accepted applicants, 88 successfully complete the certification.

Using a suitable approximation, test the instructor's claim at the 10% level of significance. State your hypotheses clearly.

[6]
Markscheme

2.4 Statistical Distributions Questions

  1. A Level
  2. /Maths
  3. /2.4 Statistical Distributions

390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank