It is known that a for a standard normal random variable X, we have E[X] = 0, E[X*] = 3, E[X] = 0, E[X] = 15. Find the correlation coefficient between X and X. Enter your answer as a number. It is known that a for a standard normal random variable X, we have E[X] = 0, E[X*] = 3, E[X] = 0, E[X] = 15. Find the correlation coefficient between X and X. Enter your answer as a number.