Final answer:
To find the value of p, we need more information. To calculate the expected value and variance of X, we require the probability distribution and values of X. The standard deviation is the square root of the variance.
Step-by-step explanation:
To find the value of p, we need more information about the context of the problem as it is not specified in the question. In order to calculate E X - the expected value of X, we would need the probability distribution of X and the values that X may take on. Then, we would multiply each value of X by its corresponding probability and sum them up to find the expected value.
To calculate E X^2, we would take each value of X, square it, multiply it by its corresponding probability, and sum them up. The variance, σ^2, is found by subtracting the square of the expected value from the expected value of X^2. Finally, the standard deviation is the square root of the variance.