1. The problem statement, all variables and given/known data Assume X is normally distributed with a mean of 10 and a standard deviation of 2. Determine the value for x that solves P(-x < X - 10 < x) = 0.95 2. Relevant equations P(X < x) = P(Z < z) = P(Z < (x - mean)/stdev) 3. The attempt at a solution P(10 -x < X < 10 + x) = 0.95 P(X < 10 + x) - P(X < 10 - x) = 0.95 P(Z < (10+x-10)/2) - P(Z < (10-x-10)/2) = 0.95 P(Z < x/2) - P(Z < -x/2) = 0.95 That's as far as I get, and then I don't know what to do next, or if what I did was correct.