Question 1
Paper 1, no calculatorMedium6 marksA grower records the irrigation time, hours, and the harvested mass, kg, for five greenhouse beds.
| 1 | 2 | 3 | 4 | 5 | |
|---|---|---|---|---|---|
| 2 | 3 | 3 | 5 | 6 |
(a)[3]
Determine, giving your working, the equation of the regression line of on in the form
(b)[1]
Hence estimate the harvested mass when the irrigation time is 4 hours.
(c)[2]
The grower wants to estimate the irrigation time from a harvested mass of kg. A trainee rearranges the equation from part (a) and obtains an estimate of 4 hours. Explain whether this is a justified use of a regression line.