Fitting a regression line to the data
So far we have been working with a simple scatter plot, but if we look at the data points on the graph, it looks like there is a fairly strong relationship between wind speed and the amount of cloud cover. Letâ€™s add a regression line to this graph and see what we get.

Rightclick in the graph and select Edit.
Note

From now on, we will omit â€˜right click in the chartâ€™ in our instructions. Unless otherwise specified, the command Edit assumes that this has been done and that we are selecting Edit from the popup menu that we first saw in Figure 59.


Select Insert > Statistics and then Linear Regression.
The linear regression line is now on the graph. This freshly invented data does show that cloud cover increases as the wind speed picks up. However, to make the graph look a little better, we should have increased the yaxis from a maximum of 50 to 55 or even 60.
Note

Calc will graph four different kinds of regression line: Linear, logarithmic, exponential and power. If you need the coefficients for these lines, you must use the statistical functions to calculate the regressions.
