constructing a standard best-fit line

[acapro]

Hi
I want to construct a standard best-fit trendline to answer the following question. A race car does 10 laps, each lap the fuel load (weight) reduces therefore the lap time reduces however the driver can not complete each lap exactly the same therefore the times do not reduce consistently. What I want to do is work out at how much time does each litre of fuel cost per lap and how much time is reduced for each lap worth of fuel

example

5 litres of fuel needed per lap

lap number
10 1:22.853
9 1:22.822
8 1:22.825
7 1:22.801
6 1:22.799
5 1:22.765
4 1:22.788
3 1:22.770
2 1:22.762
1 1:22.765

I will have 10 cells on a excel worksheet where I can enter the times next to the corresponding lap number then in the 11th cell the answer =time per lap/fuel 12th cell time per litre/fuel

Please note that the lap count works backward from a pit stop i.e lap 10 is 10 laps of fuel, lap 9 is 9 laps of fuel and so on.

I am a newbie to the world of excel so can you keep to answer as detailed and basic as possible.

Thanks in advance

 

[VoG]

Please continue in your original thread http://www.mrexcel.com/forum/excel-questions/752649-need-construct-forumla.html