Inferential Statistics and Distributions 13-29
8313INFE.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:47 PM Printed: 02/19/01 1:38 PM
Page 29 of 36
To display the DISTR menu, press y [DISTR].
DISTR DRAW
1:normalpdf( Normal probability density
2:normalcdf( Normal distribution probability
3:invNorm( Inverse cumulative normal distribution
4:tpdf( Student-t probability density
5:tcdf( Student-t distribution probability
6:c2pdf( Chi-square probability density
7:c2cdf Chi-square distribution probability
8:Üpdf( Û probability density
9:Ücdf( Û distribution probability
0:binompdf( Binomial probability
A:binomcdf( Binomial cumulative density
B:poissonpdf( Poisson probability
C:poissoncdf( Poisson cumulative density
D:geometpdf( Geometric probability
E:geometcdf( Geometric cumulative density
Note: L1å99 and 1å99 specify infinity. If you want to view the area left
of upperbound, for example, specify lowerbound
=
L1å99.
norwmalpdf( computes the probability density function
(pdf) for the normal distribution at a specified x value. The
defaults are mean
m
=0 and standard deviation
s
=1. To plot
the normal distribution, paste normalpdf( to the Y= editor.
The probability density function (pdf) is:
fx e
x
()
=>
−−
1
2
0
2
2
2
πσ σ
µ
σ
()
,
normalpdf(x[,m,s])
Note: For this example,
Xmin = 28
Xmax = 42
Ymin = 0
Ymax = .25
Tip: For plotting the normal distribution, you can set window variables
Xmin and Xmax so that the mean m falls between them, and then
select 0:ZoomFit from the ZOOM menu.
Distribution Functions
DISTR menu
normalpdf(