Question

Math question with percents

Answer 1

What do the percents mean? What would 100%?

Answer 2

The first thing I do is convert to minutes. So 12.75 is 70%. How much is 100%?

12.75 = X \* 0.70

X = 12.75 / 0.70 = 18.214+

Now that I know the whole, computing 50% of the whole is easy:

18.214+/2 = 9.107+

Is that what you need?

Answer 3

It is entirely possible the charts are referring to *percentiles*, as in the ranking of performances against all other   
 performances (for some benchmarking period), which does not let us extrapolate what 50% would be.   

IE: The threshold for the 70th percentile is 12.75 minutes (ie 30% of people run 1.5 miles in *some time that is faster than 12.75 minutes).*