Help with data arrangment for chart

I am getting stupid. Excel 2007 doesn't seem to let me do the charting I was once able to do. In Column A I have data values for mile values recorded from the satellite. In column B I have values recorded from the odometer. I want to chart the curve that represents satellite miles VS Odometer miles.

Sat Truck
116.30 111.10
168.70 161.10
195.80 187.00
206.30 197.00
210.00 200.60

As you can see it's not linear and I wanted to have excel develop the curve calculation for me. It's been 15 years since my last calculus class. What I keep getting is two lines with the Y axis being satellite miles and the X axis being the row numbers 1 through 5.

Here's what I want to do. I need to figure out what the equation is to give me actual miles (Satellite) for any given odometer reading. My tires are bigger than factory and I want actual miles for gas calculations. I know it's a curve just by looking at the data. But since it has been 15 years since my last calculus class I am getting lost here. If I drive 15 miles odometer reading what is the actual miles driven? If I have the data charted can't excel apply a trend line and give me an equation?

Thanks for your help.

can't you just simply take the average of your sat. miles, divided by the average of your odometer miles.

then, the next time you have to calculate your sat./ actual miles you can just multiple the odometer miles by your new fraction.

that's the simplest solution that you are asking for, otherwise, i'm not sure what you are trying to do with a chart.

if it's going to get increasingly larger, maybe 1 per day for 365 days, you could use a count function: (sat miles goes from a1:a365) (odo miles from b1:b365)

=(Sum(A1:A365)/Count(A1:A365))/(Sum(B1:B365)/Count(B1:B365))

this would give you the same fraction and would update to the most current/accurate mileage, allowing for variances in tire pressure, etc.

-edit added code tags.

Assuming those are comparisons taken at cumulative points, just divide the last two to get the ratio:

Please Login or Register  to view this content.

To get true mileage, multiply odo by 1.047

As you can see it's not linear

It's very linear; the deviation of the line-by-line ratios is 0.00018.

Thanks for the replies.
I could use the simplest approach, but it is not accurate enough. The difference gradually grows. This was a fun exercise so I will go back to my calc books and find the answer.
Gotta keep up the practice!

Thanks again.

The attached uses a Table for storing the 2 sets of values.
The chart is based on the table and will auto expand as more data is added.

I've used the LINEST function to return the formula values and the done a simple calculation to return estimated satellite value for given truck data.