Texas Instruments TI-84 Plus - Tpdf(; Tcdf(

Chapter 13: Inferential Statistics and Distributions 376
tpdf(
tpdf(tpdf(
tpdf(
tpdf( computes the probability density function (pdf) for the Student-t distribution at a
specified
x value. df (degrees of freedom) must be > 0. To plot the Student-t distribution,
paste
tpdf( to the Y= editor. The probability density function (pdf) is:
tpdf(x,df)
tcdf(
tcdf(tcdf(
tcdf(
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)
Note: For this example,
Xmin =
L4.5
Xmax = 4.5
Ymin = 0
Ymax = .4
f
x()
Γ df 1+()/2[]
Γ df 2⁄()
---------------------------------=
1 x
2
/df+()
df 1+()/2–
πdf
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