5.1. The Standard Normal Probability Distribution http://www.ck12.org
The first distribution pictured above has a smaller standard deviation and so the bulk of the data is concentrated more
heavily around the mean. There is less data at the extremes compared to the second distribution pictured above,
which has a larger standard deviation and therefore the data is spread farther from the mean value with more of the
data appearing in the tails.
Investigating the Normal Distribution on a TI-83/4 Graphing Calculator
We can graph a normal curve for a probability distribution on the TI-83/4. Press[y=]. To create a normal distribution,
we will draw an idealized curve using something called a density function. We will learn more about density
functions in the next lesson. The command is called a probability density function and it is found by pressing[2nd]
[DISTR] [1]. Enter anXto represent the random variable, followed by the mean and the standard deviation. For
this example, choose a mean of 5 and a standard deviation of 1.