Practice variation 2 of 3
Binomial distribution — New $n$ and threshold
Your question
A plant claims of items pass inspection. In a sample of items, fail.
(i) Using the normal approximation to the binomial (without continuity correction), calculate where is the number of failures under the claim. Hence,
(ii) Explain why the normal-approximation method might not be valid.
This practice question was inspired by Question 13(e) in the 2022 NSW HSC Mathematics Extension 1 examination, © NESA. It is an original TestMum variation that practises the same mathematical idea, not an official NESA question.
Before you check
- Have you stated every choice or assumption?
- Can another student follow each line?
- Did you verify the final result independently?