(c) Let the output value of Company B in the first quarter be A and that of Company A be 0.8a.

So in the second quarter, the output value of company B is 1. 1a, and that of company A is 0.8a? 1.2

So the ratio of output value in the second quarter is 0.96: 1. 1=48:55.

In the second quarter, the output value of Company A increased by 20% compared with the first quarter. Your method is equivalent to two unrelated groups. Pay attention to the meaning of "a" in the question of proportion.