Jokes about car rental fees

(1) Both parties pay the same fee, which is 2.46 yuan ... (2 points)

The probability of paying 2 yuan is p1=1.4×1.2 =1.8;

The probability of paying 4 yuan is P2 =12×14 =18;

The probability of paying 6 yuan is P3 =14×14 =116;

So the same payment probability is p = p1+p2+P3 = 516 ... (6 points).

(2) According to the meaning of the question, the possible values of ξ are 4, 6, 8, 10, 12...(8 points).

p(ξ= 4)= 1 8； p(ξ= 6)= 1 4× 1 4+ 1 2× 1 2 = 5 16；

p(ξ= 8)= 1 4× 1 4+ 1 2× 1 4+ 1 2× 1 4 = 5 16； p(ξ= 10)= 1 4× 1 4+ 1 2× 1 4 = 3 16；

p(ξ= 12)= 1 4× 1 4 = 1 16。

Therefore, what is the distribution list of ξ? ξ 4 ? 6 ? 8 10 ? 12 ? p？ 1 8 ? 5 16 ? 5 16 ? 3 16 1 16 ...( 1 1)

Mathematical expectation e ξ = 4×18+6× 516+8× 516+10× 316 =