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
