Answer:
13
Step-by-step explanation:
Pythagreom Therom:
a^2+b^2=c^2
12^2+5^2=c^2
144+25=c^2
169=c^2
c=13
28 are 6th
14 and 7th
40% are 8th
the unit rate is 2.25
4×2.25=9.0
6×2.25=13.5
8×2.25=18.0