A retail manager collected data on the floor space (xxx) and the average weekly revenue (yyy) of 12 branches of a clothing store chain.
| Floor Space (100 m2) | 1.2 | 1.5 | 1.8 | 2.0 | 2.5 | 3.0 | 3.2 | 3.5 | 4.0 | 4.2 | 4.8 | 5.5 |
| Weekly Revenue (£1000 £1000\,£1000s) | 8 | 10 | 11 | 14 | 15 | 19 | 18 | 22 | 25 | 24 | 28 | 32 |
Draw a scatter graph for this information.
Give an interpretation of the correlation between floor space and weekly revenue.
The equation of the regression line for this data is y=5.62x+1.85y = 5.62x + 1.85y=5.62x+1.85.
Give an interpretation of the gradient of this regression line.
The product moment correlation coefficient is calculated to be 0.96.
Stating your hypotheses clearly, test at the 5% significance level whether there is a positive correlation between floor space and revenue.
Determine whether you would reach the same conclusion at the 1% significance level.
355 exam-style questions on OCR (MEI) A Level Maths 2.5 Statistical Hypothesis Testing, covering 2.5.1 Process and language of hypothesis testing, 2.5.2 When to apply 1-tail and 2-tail tests, 2.5.3 Significance level and incorrect rejection, 2.5.4 Null and alternative hypotheses (binomial), 2.5.5 Conduct a binomial hypothesis test, 2.5.6 Critical and acceptance regions (binomial), 2.5.7 Distribution of the sample mean (A-level only), 2.5.8 Hypothesis test for a single mean (A-level only), 2.5.9 Critical and acceptance regions (mean) (A-level only), 2.5.10 Correlation as closeness to a straight line (A-level only), 2.5.11 Inference using a correlation coefficient (A-level only), and 2.5 Statistical Hypothesis Testing. Each one has a worked solution and a mark scheme showing where the marks go.