Given: X is N(1, 4).
P(1 < X^2 < 9) = 0.3413447 -> seven decimal places pnorm(√(9), 1, 4) - pnorm(√(1), 1, 4) + pnorm(-√(1), 1, 4) - pnorm(-√(9), 1, 4)
equivalent simplified expression pnorm(3, 1, 4) - pnorm(1, 1, 4) + pnorm(-1, 1, 4) - pnorm(-3, 1, 4)
