The discrete random variable X X\,X has the distribution X∼B(20,0.41)X \sim B(20, 0.41)X∼B(20,0.41).
Find P(3<X≤7)P(3 < X \le 7)P(3<X≤7).
A restaurant's records show that 30% of its customers order a starter. On one day a random sample of 50 customers is taken, and 9 of them order a starter. Stating your hypotheses clearly, test at the 5% significance level whether the proportion of customers ordering a starter has decreased.
162 exam-style questions on AQA A Level Maths 2.5 O: Statistical hypothesis testing, covering 2.5.1 Language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, and 2.5.3 Hypothesis test for a Normal mean (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.