# What is a normal probability curve?

##### 1 Answer

Normal probability curve is the plot of probability density function of the normal distribution. This probability curve is bell shaped, has a peak at mean

Following is the formula.

Following is an example of a normal probability curve with mean

graph{1/sqrt(2*pi) * (e^((-x^2)/2)) [-4, 4, -0.2, 0.5]}

Following is an example of a normal probability curve with mean

graph{1/sqrt(2*pi*15^2) * (e^((-(x-100)^2)/(2*15^2))) [40, 160, -0.007, 0.05]}

It might be hard to notice but the second graph is a lot more spread out.