a=200×0.25=50，

b=48200=0.24，

c = 200×0. 15 = 30；

So the answer is: 200, 50, 0.24, 30;

(2) The frequency of 60.5-70.5 is16200 = 0.08;

(3) Number of outstanding students: 8000× (0.24+0.15) = 3120,

A: There are about 365,438+020 students with excellent math scores in the city.