In the OCR large data set, 243 of the 348 local authorities in 2001 had at least 8% of employed people working mainly at or from home. This proportion is 0.698 to 3 significant figures and is to be modelled as 0.70.
Jo takes a simple random sample of 30 local authorities from the 2011 data. Of these, 22 have at least 8% of employed people working mainly at or from home. She tests whether the corresponding proportion has changed, using a 10% significance level and a probability of at most 0.05 in each tail.
State suitable null and alternative hypotheses for Jo's test, defining the parameter used.
Using a 10% significance level, find the critical region for Jo's test.
State Jo's conclusion in context.
316 exam-style questions on OCR A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 The language of hypothesis testing, 2.5.2 Hypothesis test for a binomial proportion, 2.5.3 Inference and significance level, 2.5.4 Sample mean as a random variable (A-level only), 2.5.5 Hypothesis test for the mean of a normal distribution (A-level only), 2.5.6 Pearson's product-moment correlation coefficient, and 2.5.7 Hypothesis test using Pearson's coefficient (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.