State the conditions under which a normal distribution can be used as a suitable approximation for a binomial distribution B(n,p)B(n, p)B(n,p).
A wholesale seed distributor claims that 35% of the seeds in their 'Azure Meadow' mix will produce blue-petalled flowers.
Explain why the distributor should not test every seed in a batch to verify this specific claim.
To investigate the distributor's claim, a researcher selects a random sample of 400 seeds and grows them under controlled conditions.
State the null and alternative hypotheses for a two-tailed test of the distributor’s claim.
Of the 400 seeds sampled, 156 were found to produce blue-petalled flowers.
Use a normal approximation to test, at the 5% level of significance, whether there is evidence to suggest the distributor's claim is incorrect.
390 exam-style questions on OCR A Level Maths 2.4 Statistical Distributions, covering 2.4.1 Discrete probability distributions, 2.4.2 Binomial distribution as a model, 2.4.3 Calculating binomial probabilities, 2.4.4 Mean and variance of the binomial (A-level only), 2.4.5 Normal distribution as a model (A-level only), 2.4.6 Probabilities using the normal distribution (A-level only), 2.4.7 Links to histograms, mean and standard deviation (A-level only), and 2.4.8 Selecting an appropriate distribution (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.