How do i draw the normal curve?

jim1174 · Joined: 05 Dec 2007 Posts: 1

Useing my ti-89 titanium how do i draw the normal curve with the parameters indicated. shade the area that represents the probability

mean=20 standerd deviation=3 P(22 ≤ X ≤ 27)

DifEqRules · Joined: 29 Apr 2009 Posts: 7

If I remember right, y = 1/sqrt(2 pi) e^(-(x-m)^2) is the graph with mean m and standard deviation 1.

I'm not sure where the standard deviation comes into play and how to shade. wikipedia.org is a great place for math (non-calculator) help. If you do a search there under normal curve, you might find the formula for any standard deviation.

BlainUSM · Joined: 24 Oct 2009 Posts: 30 Location: New England

I'm assuming that your TI-89 has the "Stats/List Editor" installed. If so, enter the following at the homescreen:

TIStat.shadNorm(22,27,20,3,1)

The "1" is a scaling parameter. You may also elect to use the "Stats/List Editor" directly (under the "APPS" menu). If you can't see the graph, you may need to adjust your window settings.

*Tip: to avoid typing the lengthy name "TIStat.shadNorm(" you may select it from the catalog with the (slightly shorter) key sequence:

"CATALOG", "F3", "ALPHA", "ALPHA", "R", "2nd", "Down", "Down", "ENTER"