State the conditions under which the normal distribution may be used as an approximation to the binomial distribution.
A manufacturer of electric components claims that 45% of their batch of sensors are high-precision.
Explain why the company should not test every sensor produced to verify this claim.
To test the manufacturer's claim, a random sample of 300 sensors was tested.
State the hypotheses for a two-tailed test of the company’s claim.
Given that 150 of the 300 sensors were found to be high-precision,
use a normal approximation to test, at the 10% level of significance, whether or not the manufacturer's claim is justified.
67 exam-style questions on OCR A Level Maths 2.4.4 Mean and variance of the binomial (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.