Mastering the Calculator using the Casio fx-82MS
25
10.
Statistics
10.1 Mean and standard deviation – single data
The formula for the mean is
The formulas for the sample standard deviation are
(sample)
(population)
Your calculator will calculate the mean and standard deviation for you (the population
standard deviation
or the sample standard deviation
– in data calculations you will
usually use the sample standard deviation.)
On the Casio fx-82MS,
σ
and s are found in s-VAR. The positions of keys needed are shown on
the diagram below.
x
Σ
x
n
------
=
2
1
1
or
1
n
x
x
s
n
σ
⎛
⎞
⎜
⎟
⎜
⎟
⎝
⎠
−
−
=
−
∑
2
1
=
n
x
x
n
σ
⎛
⎞
⎜
⎟
⎜
⎟
⎝
⎠
−
∑
σ
n
σ
n-1
input data key
(key for mean, sample
and population standard
deviation)
(Key for sum of observations,
sum of observations squared, and number of
observations)