A biology student tracked the growth of 12 sunflowers over two months. The table below shows the age of the sunflowers in days and their corresponding height in cm.
| Age (days) | 5 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 |
| Height (cm) | 12 | 22 | 34 | 45 | 58 | 68 | 79 | 85 | 96 | 108 | 115 | 128 |
Draw a scatter graph for this information.
Give an interpretation of the correlation between the age and the height of the sunflowers.
The equation of the regression line is h=2.10d+2.50h = 2.10d + 2.50h=2.10d+2.50, where h h\,h is height and d d\,d is age in days.
Give an interpretation of the gradient of this regression line.
The product moment correlation coefficient for this data is calculated to be 0.94.
Stating your hypotheses clearly test, at the 5% significance level, whether there is a positive correlation between age and height.
Determine whether you would reach the same conclusion at the 1% significance level.
202 exam-style questions on Edexcel A Level Maths Regression, Correlation and Hypothesis Testing, covering 1.1 Exponential Models, 1.2 Measuring Correlation, and 1.3 Hypothesis Testing for Zero Correlation. Each one has a worked solution and a mark scheme showing where the marks go.