Since x>0, you could try a log scale.

What would a log scale do? I don't remember them too well from school apart from making a curving increasing line.

I've attached a drawing of what I want. I'm sure its simple.

X and Y are both the same scale on each set, I just want each point on the graph to correspond to the correct x/y value.

Oh, hang on, I think I just figured out your problem. It's not the scale so much as getting both sets of data onto the graph. Correct?

If that's the case, create a table with four columns. Time1, Temp1, Time2, Temp2. Create the scatter plot with Temp1 vs Time1. Then select the graph, right click, and 'select data set' (or something like that, I'm doing this from memory). In the dialogue box create a new data set and set the x to be the Time2 column/boxes, and y to be the matching temp.

I thought the problem was the scale. See ^

That's what I want, yeah. I'll give that a go, thanks.

That's perfect. Thank you. I knew there'd be a simple solution but couldn't work it out. Thanks :)

Another quick workaround for stuff like this would be doing two graphs and super-imposing in your graphics editor.

Obviously not ideal for ongoing changing stuff, but worth remembering you don't always to stick to a spreadsheet. Trend lines are a good example of something that can be a PITA to get right at times, but are easily drawn with vectors.

Select data, right click, add trend line, select trend line that best fits the data. Gives you equation and R² to boot. What's so difficult about that?

Ah, right. Also thought it was the scale.

I don't think I explained it very well.

No, I don't think you did, Christopher :C

I also assumed that everyone knows you right click a plot area and choose select data to tell excel what to plot.

:( I've either been naughty or you're my grandmother.

Select data, not add more data. They should make it more obvious.

> select trend line that best fits the data

You either have significantly more options than I, or have only ever dealt with boring data.

My Excel gives me exponential, linear, logarithmic, 5 orders of polynomial, power, and several orders of moving average (I've never figured the point of that). I'm sorry that your Excel is broken Paeter. I'm also sorry that your data are not as boring as mine. You live an exciting life.

What are your views on pizza Napoli?