If you have the miles biked in column A starting with A2 and the time
for each distance in B, then in C2 enter =SUM($A$2:A2)/SUM($B$2:B2)/24.
Drag this down column C for as many races as you have. It gives the
unweighted average for all races in rows 2:n.

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Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
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In article ,
says...
I bike race and like to keep track of average speed of the races. I'd like
to set up a template in Excel that I can easily enter the time and distance
and let the spreadsheet do the figuring. I have a template now, but have to
enter many different numbers to convert the time to decimal numbers and the
formulas are long and cumbersome.