Tpdf, Tcdf – Texas Instruments TI-84 User Manual
Page 379
Chapter 13: Inferential Statistics and Distributions
376
tpdf(
tpdf(
tpdf(
tpdf(
tpdf(
computes the probability density function (
) 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 (
) 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 =
L
4.5
Xmax = 4.5
Ymin = 0
Ymax = .4
f x
( )
Γ df 1
+
(
)/2
[
]
Γ df 2
⁄
(
)
---------------------------------
=
1
x
2
/df
+
(
)
df
1
+
(
)/2
–
πdf
-------------------------------------------------