Beijing smog weather statistics

(1) Using histogram and pie chart, we can draw the following conclusions:180 ÷ 45% = 400;

m=60400× 100%= 15%，n = 1-5%- 15%-45% = 35%；

(2) The central angle of sector D in the sector statistical chart shown in Figure 2 is: 360× 35% =126;

(3) The number of people with grade÷Dis: 400× 35% =140;

As shown in the figure:

(4) Column chart:

So it can be seen from the tree diagram that there are 12 possible results, and the sum of 8 kinds is odd.

Then the probability of Xiaoming's participation is: P=8 12=23,

The probability of Xiaogang's participation is: P=4 12= 13,

So the rules of the game are unfair.

So the answer is: 400, 15%, 35%; 126.