A graph helps to analyse data and can be used to draw a conclusion.
When plotting a graph:
A lot can be learnt by looking at the shape of a graph. The gradient is the slope of the graph. For example, when looking at a graph of mass produced against time, the gradient of the graph shows the mass produced per second. This is the rate of reaction.
How does the rate of reaction change over time?
Finding values within the range originally measured is called interpolation.
To interpolate a graph, read up from the horizontal axes, then across to find the new value.
Finding values beyond the range that was originally measured is called extrapolation.
To extrapolate a graph, first extend the line. Then read up from the horizontal axis and across to find the new value.