During her 8th week of training a woman ran 20 total miles, during her 13th week of training she ran 33 total miles.
if the woman ran 37 miles, what week of training would she be in

So 8th week:20
13th week:33
13-8=5
33-20=13
grouth of 13 per 5 weeks or about 2.6 increse per week

so if she ran 37 miles then
37-33=4
so an increse of 4 or about 1.5 more weeks soweek 14.5

another way is to find the ratio of miles to weeks
20/8=2.5
33/13=2.54
average 2.5 and 2.54 and get 2.52
37/x=2.52
solve for x
37/x=2.52
multiply both sides by x
37=2.52x
divide both sides by 2.52
14.68=x
she is on her 14.68 week
you might want to round up