(1) There are 6 excellent products in the samples taken from a factory, and the rate of excellent products is 6 10 = 35.

There are 5 excellent products in the samples taken by Factory B, and the rate of excellent products is 5 10 = 12...(2 points).

(2) The value of ξ is 0.1.2,3.

P(ξ= 0)= c 05 c35 c 3 10 = 1 12，P(ξ= 1)= c 15 c25 c 3 10 = 5 12，

P(ξ= 2)= c25c 15c 3 10 = 5 12，P(ξ= 3)= c35c 3 10 = 1 12。

So the distribution list of ξ is

ξ 0 1 ? 2 ? 3P 1 12？ 5 12 5 12 1 12? Therefore, e ξ = 0×112+1× 512+2×.