5.2. The Density Curve of the Normal Distribution http://www.ck12.org
5.2 The Density Curve of the Normal Distribu-
tion
Learning Objectives
- Identify the properties of a normal density curve, and the relationship between concavity and standard devia-
tion. - Convert betweenz−scores and areas under a normal probability curve.
- Calculate probabilities that correspond to left, right, and middle areas from a left-tailz−score table.
- Calculate probabilities that correspond to left, right, and middle areas using a graphing calculator.
Introduction
In this section we will continue our investigation of normal distributions to include density curves and learn various
methods for calculating probabilities from the normal density curve.
Density Curves
Adensity curveis an idealized representation of a distribution in which the area under the curve is defined to be 1.
Density curves need not be normal, but thenormal density curvewill be the most useful to us.