Does anyone know Experimental Probability?

You suspect that a coin is not fair. Which statement would provide the best evidence that the coin is unfair?

A. You flip the coin 25 times and observe 13 heads

B. You flip the coin and observe 4 consecutive heads

C. You flip the coin 10 times and observe 8 heads

D. You flip the coin 100 times and observe 72 heads

A. You flip the coin 25 times and observe 13 heads, then the probability to get head is 13/25 (very close to theoretical probability 1/2).

B. You flip the coin and observe 4 consecutive heads. This statement may occur to be true, because next 4 could be consecutive tails.

C. You flip the coin 10 times and observe 8 heads, then the probability to get head is 8/10=4/5.

D. You flip the coin 100 times and observe 72 heads, then the probability to get head is 72/100=18/25.

Since 1/2<18/25<4/5, you can conclude that the best evidence that the coin is unfair provides statement C.

Answer: correct choice is C.