Normal Curve Formula

f(x) = height of the normal curve on the vertical axis for a value x

x = a value on the horizontal axis

μ = mean of the normal distribution

σ = standard deviation of the normal distribution

π = 3.14159… (mathematical constant)

e = 2.71828… (mathematical constant)

If we know the mean, μ, and standard deviation, σ, for a normal distribution, then we know everything about the distribution. We can compute the probability of observing an x score above or below any specific value. Fortunately, tables and computer programs are available to help us find these values.