According to Wikipedia, PP is the class of decision problems solvable by a probabilistic Turing machine in polynomial time, with an error probability of less than 1/2 for all instances. If the answer is YES, the algorithm will answer YES with probability more than 1/2. If the answer is NO, the algorithm will answer YES with probability less than or equal to 1/2.So, the problem is to prove that if in definition we change probability from 1/2 to any rational number (0,1) we obtain the same class of problems.
Prove that we can change probability in definition of PP class
complexity theory;complexity classes;probabilistic algorithms