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2.4.4 Mean and variance of the binomial (A-level only)

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Question 3

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]

2.4.4 Mean and variance of the binomial (A-level only) Questions

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