Practice variation 1 of 3
Binomial distribution — Different sample and rate
Your question
A bakery claims of loaves meet the minimum weight. Inspectors sample loaves and find underweight.
(i) Using the normal approximation to the binomial (without continuity correction), calculate the probability of at least underweight loaves in a sample of , assuming the claim (underweight rate ). 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?