Chapter 13: Inferential Statistics and Distributions
249
Note:
Before you execute a
DISTR DRAW
instruction, you must set the window variables so that the
desired distribution fits the screen.
DISTR DRAW
1: ShadeNorm(
Shades normal distribution.
2: Shade_t(
Shades Student-
t
distribution.
3: Shade
c
2
(
Shades
c
2
distribution.
4: Shade
Ü
(
Shades
Ü
distribution.
Note:
L
1
â
99 and 1
â
99 specify infinity. If you want to view the area left of
upperbound
, for example,
specify
lowerbound
=
L
1
â
99.
ShadeNorm(
ShadeNorm(
draws the normal density function specified by mean
m
and standard deviation
s
and
shades the area between
lowerbound
and
upperbound
. The defaults are
m
=0 and
s
=1.
ShadeNorm(
lowerbound
,
upperbound
[
,
m
,
s
]
)
Classic
Note:
For this example,
Xmin = 55
Xmax = 72
Ymin =
L
.05
Ymax = .2
Shade_t(
Shade_t(
draws the density function for the Student-
t
distribution specified by
df
(degrees of
freedom) and shades the area between
lowerbound
and
upperbound
.
Shade_t(
lowerbound
,
upperbound
,
df
)
Classic
Note:
For this example,
Xmin =
L
3
Xmax = 3
Ymin =
L
.15
Ymax = .5