Statistics Programs 16–17
55
g
@
)
Stores 55 for the mean.
15.3
g
)
Stores 15.3 for the standard
deviation.
X
D
%@
value
Starts the distribution program and
prompts for
X.
90
g
/
)
Enters 90 for X and calculates Q(X).
Thus, we would expect that only about 1 percent of the students would do better
than score 90.
Keys:
(In RPN mode)
Display: Description:
X
I
@
)
Starts the inverse routine.
0.1
g
%/
)
Stores 0.1 (10 percent) in Q(X) and
calculates
X.
g
@
)
Resumes the inverse routine.
0.8
g
%/
)
Stores 0.8 (100 percent minus 20
percent) in
Q(X) and calculates X.
Grouped Standard Deviation
The standard deviation of grouped data, S
xy
, is the standard deviation of data
points
x
1
, x
2
, ... , x
n
, occurring at positive integer frequencies f
1
, f
2
, ... , f
n
.
¦
¦
¦
¦
−
−
=
1
2
2
)f(
f
)fx(
fx
S
i
i
ii
ii
xg
This program allows you to input data, correct entries, and calculate the standard
deviation and weighted mean of the grouped data.
