Texas Instruments TI-83

Inferential Statistics and Distributions 13-31

8313INFE.DOC TI-83 international English Bob Fedorisko Revised: 02/19/01 12:47 PM Printed: 02/19/01 1:38 PM

Page 31 of 36

tcdf( computes the Student-t distribution probability

between lowerbound and upperbound for the specified df

(degrees of freedom), which must be > 0.

tcdf(lowerbound,upperbound,df)

c2pdf( computes the probability density function (pdf) for

the c2 (chi-square) distribution at a specified x value. df

(degrees of freedom) must be an integer > 0. To plot the c2

distribution, paste c2pdf( to the Y= editor. The probability

density function (pdf) is:

fx df xex

df df x

() ()

(1/2)=≥

−−

2212

Γ/,

// /

c2pdf(x,df)

Note: For this example,

Xmin = 0

Xmax = 30

Ymin = L.02

Ymax = .132

c2cdf( computes the c2 (chi-square) distribution probability

between lowerbound and upperbound for the specified df

(degrees of freedom), which must be an integer > 0.

c2cdf(lowerbound,upperbound,df)

tcdf(

2pdf(

2cdf(