Answer:
He thought that 85% of them were very good.
4√5
Step-by-step explanation:
Use Pythagorean theorem
a^2=21^2-19^2
a^2=441-19^2
a^2=441-361
a^2=80
a= √80
simplify
46.32 + (46.32 *.375)
46.32 + 17.37
=63.69