Question 1
Paper 2, calculatorMedium12 marksA teacher records, for seven students, the number of optional online revision sets each student completed and the student’s examination mark out of 100. The students chose how many sets to complete.
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | |
|---|---|---|---|---|---|---|---|
| 52 | 56 | 59 | 65 | 66 | 72 | 74 |
Sketch a scatter diagram for the data.
Use your GDC to determine Pearson’s product-moment correlation coefficient and the equation of the regression line of on Give all values to three significant figures.
Use the regression line to estimate the examination mark for a student who completes 6 revision sets. Interpret the gradient of the regression line in this context.
Use the regression line to estimate the examination mark for a student who completes 12 revision sets. Comment on the reliability of this estimate and on the claim that completing more revision sets causes higher examination marks.