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

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Question 10

An automated agricultural research system monitors large batches of seedlings for a rare genetic mutation. This mutation occurs independently in each seedling with a probability of 0.08.

a.

Determine the probability that in a randomly selected batch of 25 seedlings, exactly 3 will possess this mutation.

[3]
b.

Batches are grouped into larger delivery trays, each containing 50 seedlings. A quality control inspector selects 5 of these trays at random.

Find the probability that exactly two of these trays will contain more than 6 seedlings with the mutation.

[4]
c.

A high-capacity growing facility contains n n\,n seedlings of a different strain, where the probability of the mutation is 0.2.

Using a normal approximation, the probability that this facility contains more than 91 seedlings with the mutation is 0.0749.

Find the value of nnn.

[5]

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

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  3. /2.4.4 Mean and variance of the binomial (A-level only)