The scatter diagram shows the number of hours of sunshine and the number of visitors, in hundreds, at a beach on each of twelve days. A line of best fit has...

(a) The points rise from lower left to upper right: more hours of sunshine goes with more visitors. That is positive correlation [B1]. Correlation describes the direction of the trend, so the answer is a type, not a number.

(b) Use the line of best fit, not an individual plotted day. Find \(7\) on the hours axis, go vertically up to the line, then horizontally across to the visitors axis [M1]. The reading is

Any value from \(5.2\) to \(5.6\) is accepted, since a hand-drawn line and a reading between gridlines carry a small tolerance. The axis is already in hundreds, so the answer is left as \(5.4\) hundred rather than converted.

(c) Two separate reasons are needed:

• \(15\) hours is outside the range of the data collected, so using the line there is extrapolation rather than reading within the evidence [B1].
• The trend may not continue beyond the days that were recorded, for example the beach has a limited capacity, so the straight-line pattern cannot be assumed to hold [B1].

Saying "the line does not reach \(15\)" twice in different words scores once only. Give one reason about the data range and one about the trend not continuing.