A teacher recorded the number of hours spent on revision and the exam scores (%) of 12 students. The data is presented below.
| Revision (hrs) | 5 | 8 | 10 | 12 | 15 | 18 | 20 | 22 | 25 | 28 | 30 | 35 |
| Score (%) | 35 | 42 | 48 | 52 | 58 | 65 | 68 | 74 | 78 | 85 | 88 | 95 |
Draw a scatter graph for this information.
Give an interpretation of the correlation between revision hours and exam scores.
The equation of the regression line is s=1.95h+24.8s = 1.95h + 24.8s=1.95h+24.8, where s s\,s is the score and h h\,h is hours.
Give an interpretation of the gradient of this regression line.
The product moment correlation coefficient is calculated to be 0.86.
Stating your hypotheses clearly test, at the 5% significance level, whether there is a positive correlation between revision hours and exam scores.
Determine whether you would reach the same conclusion at the 1% significance level.
Practise Edexcel A Level Maths Regression, Correlation and Hypothesis Testing with exam-style questions for A Level Maths. 100 questions covering Exponential Models, Measuring Correlation, and Hypothesis Testing for Zero Correlation, matched to the Edexcel A Level Maths (9MA0) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.