Texas Instruments TI-82 STATS

13–30 Inferential Statistics and Distributions
8250FC~1.DOC TI-83 international English Bob Fedorisko Revised: 10/26/05 1:39 PM Printed: 10/27/05 2:57
PM Page 30 of 36
normalcdf( computes the normal distribution probability
between lowerbound and upperbound for the specified mean
m
and standard deviation s . The defaults are m =0
and
s =1.
normalcdf(lowerbound,upperbound[, m , s ])
invNorm( computes the inverse cumulative normal distribution
function for a given area under the normal distribution curve
specified by mean
m and standard deviation s . It calculates the x
value associated with an area to the left of the x value.
0  area  1 must be true. The defaults are
m =0 and s =1.
invNorm(area[, m , s ])
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:
fx
df
df
xdf
df
df
()
[( ) ]
()
()
()
=
++
−+
Γ
Γ
12
2
1
2
12
/
/
/
/
π
tpdf(x,df)
Note: For this example,
Xmin = L4.5
Xmax = 4.5
Ymin = 0
Ymax = .4
Distribution Functions (continued)
normalcdf(
invNorm(
tpdf(