Normal Fit
The normal/observed histogram
represents the most common graphical test
of normality. When you select this fit, a normal curve will be overlaid
on the frequency distribution. The curve is drawn as a Custom Function
(the equation can be reviewed or edited in the User-Defined Function dialog).
The normal function fitted to histograms is defined as:
f(x) = NC * step * normal(x,
mean, std.dev.)
The normal function fitted to cumulative histograms is defined as:
f(x) = NC * inormal(x,
mean, std.dev.)
where
NC |
is the number of cases. |
step |
is the categorization step
size (e.g., the integral categorization step size is 1). |
normal |
is the normal function. |
inormal |
is the integral of the normal
function. |
See also, 2D Histograms,
Normal Distribution and Bivariate
Normal Distribution.