Question 1
Paper 2Easy6 marksA technician records the volume of water in a container as it is filled. Let be the time, in minutes, after filling begins, and let be the volume of water, in litres.
| 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | |
|---|---|---|---|---|---|---|---|---|
| 10 | 17 | 27 | 30 | 44 | 46 | 60 | 64 |
(a)[2]
Use a GDC to calculate Pearson’s product-moment correlation coefficient, to three significant figures. Describe the direction and strength of the linear correlation.
(b)[1]
Use a GDC to find the equation of the regression line of on giving its coefficients to four significant figures.
(c)[1]
Use your regression line to estimate the volume of water after 9 minutes. Give your answer in litres to three significant figures.
(d)[2]
Interpret the gradient and the vertical intercept of the regression line in this context.