Normal Distribution: Areas to the Left and Right of x
1.5
2008/06/06 14:39:08 GMT5
2008/10/27 18:41:33.307 GMT5
Susan
Dean
deansusan@deanza.edu
Barbara
Illowsky
illowskybarbara@deanza.edu
Susan
Dean
deansusan@deanza.edu
Barbara
Illowsky
illowskybarbara@deanza.edu
Connexions
cnx@cnx.org
elementary
statistics
The arrow in the graph below points to the area to the left of x. This area is
represented by the probability
P
(
X
x
)
.
Normal tables, computers, and calculators
provide or calculate the probability
P
(
X
x
)
.
The area to the right is then
P
(
X
x
)
=
1

P
(
X
x
)
.
Remember,
P
(
X
x
)
=
Area to the left of the vertical line through x.
P
(
X
x
)
=
1

P
(
X
x
)
=
.
Area to the right
of the vertical line through x
P
(
X
x
)
is the same as
P
(
X
x
)
and
P
(
X
x
)
is the same as
P
(
X
x
)
for continuous distributions.