Calculate consistency (efficiency?) in a column of numbers?

[jbrow1]

I have a spreadsheet full of lap-times on a race track. I was wondering if there was a function or way I can use excel to analyze the numbers in a column and come up with a consistency or efficiency rating for each set of laps?

Average lap-time is great to know, but it tells nothing about the spread between the individual laps.

Thought maybe someone here might have an idea of what I'm looking for. I'm actually a little unsure myself. I just know there's something I'm missing while analyzing my data.

Any ideas are greatly appreciated

[Richard Buttrey]

Have you considered the standard deviation measure? This will tell you for various confidence levels the spread of lap times that you can expect.

[Pete_UK]

You could look for the MIN and MAX of the times. Using that you could produce a table with appropriate time increments for each row, and count how many fall within each increment. From that you could display the counts graphically as a histogram. If you attach a sample Excel workbook we can show you how to achieve those things (and maybe a few others).

To do this, click on Go Advanced (below the Edit Window) while you are composing a reply, then scroll down to and click on Manage Attachments and the Upload window will open. Click on Browse and navigate to (and double-click) the file icon that you want to attach, then click on Upload and Close this Window to return to the Edit window. When you have finished composing your post, click on Submit Post.

Pete

[jbrow1]

Thanks for the replies. I will search on the standard deviation this evening and see what that is.

I'll attach a couple of sets of lap-times to this post. The first set was quite consistent, and resulted in an extra lap.
The next was not bad, but had 1 or 2 bad laps. I guess I'm just looking for a way to analyze those laps to quickly see that
you (I) were a lap short because your laps were only within xx% of each other.

[jbrow1]

Have you considered the standard deviation measure? This will tell you for various confidence levels the spread of lap times that you can expect.

Thanks for the tip Richard. I have added the standard deviation into my spreadsheets. Also had another tip of dividing the fast lap by the average lap and using that as an "error factor."
Now to start cleaning up my spreadsheet and making it more friendly. Thanks folks