In May of 20 14, Nanchang City of our province was hit by heavy rain for several days. A website asked, "Do people support increasing investment in building urban underground drainage facilities?"

(1) Let "take any vote from all the votes and get the vote that does not support investment" as event a,

From the known P(A)=y+30 100=25,

So y= 10, B=40, x=40, A=60? ... 6 points

(2)x2= 100×(30×40？ 20× 10)250×50×40×60≈ 16.67>6.635,

Therefore, it is at least 99% sure that the rainstorm in Nanchang is related to whether the people agree to increase the investment in urban underground drainage facilities ... (12 points)