Right, keep it steady for the computer and maths illiterate (apparently I should be using something called Minitab but that doesn't do anything right, so I've fallen back on Excel).
I want to fit a trend line (?) to a graph. My graphlooks like this at the minute-

And I want a nice red line like this going through it all-

How do I do that?
Also, while I'm here, what sort of measure of central tendancy do I want to use for that sort of data (interval scale- I think that's it)- my reckoning says the mode, but that doesn't seem right.
Thanks in advance.

