Standard deviation calculation, Regression calculation, Probability – CITIZEN SR-270II User Manual
Page 6: Other functions ( x
6
x + y i= r (cos
θ
+ i sin
θ
)
• The calculator can perform the conversion between rectangular coor-
dinates and polar coordinates by [ ALPHA ] [ Pol ( ] and [ ALPHA ]
[ Rec ( ]. Calculation results are automatically stored in memory vari-
ables E and F. See Example 31~32.
(Note) :When using those key, make sure the calculator is set for the
angle unit you want.
Probability
• This calculator provides the following probability functions : ( See
Example 33~36.)
[ nPr ]
Calculates the number of possible permutations of n
item taken r at a time.
[ nCr ]
Calculates the number of possible combinations of n
items taken r at a time.
[ x! ]
Calculates the factorial of a specified positive inte-
ger x , where x < 69.
[ RANDOM ]
Generates a random number between 0.000 and 0.999
Other functions ( x
–1
,
,
3
,
X
, x
2
, x
3,
x
y
)
• The calculator also provides reciprocal ( [ x
–1
] ), square root ([
]),
cubic root ( [
3
] ), universal root [
X
], square ( [ x
2
] ), cubic
( [ x
3
] ) and exponentiation ( [ x
y
] ) functions. See Example 37~40.
Standard Deviation Calculation
☺
Use the SD mode for standard deviation
calculations.
• Always make sure you clear statistical memory by [ 2nd ] [ Scl ] before
preforming standard deviation calculation.
• Individual data can be input using [ DT ] ; To delete data you just input,
please press [ 2nd ] [ CL ]. Multiple data of the same value can be input
using [ 2nd ] [
;
]. For example, to input the data 15 seven times, press
15 [ 2nd ] [
;
] 7 [ DT ].
• The values of the statistical variables depend on the data you input. You
can recall them by the key operations shown in the below table. See
Example 41.
∑
x
2
[ RCL ] + [ A ]
−
x
[ 2nd ] + [
−
x ]
∑
x
[ RCL ] + [ B ]
X
σ
n
[ 2nd ] + [ X
σ
n
]
n
[ RCL ] + [ C ]
X
σ
n-1
[ 2nd ] + [ X
σ
n-1
]
Regression Calculation
☺
Use the REG mode for regression calculations.
Press [ MODE ] 3 to enter the REG menu and then choose one of the six
regression types by pressing the corresponding argument value, as fol-
low :
3
2
1
Exp
Log
Lin
←
→
]
[
]
[
3
2
1
Quad
Inv
wr
P
Lin
Linear Regression
y = A + B x
Log
Logarithmic Regression
y = A + B lnx
Exp
Exponential Regression
y = A • e
Bx
Pwr
Power Regression
y = A • x
B
Inv
Inverse Regression
y = A +
x
B
Quad
Quadratic Regression
y = A + B x + C x
2
• Always make sure you clear statistical memory by [ 2nd ] [ Scl ] before
preforming regression calculation.
• Individual data can be input using [ DT ] ; To delete data you just input,
please press [ 2nd ] [ CL ]. Multiple data of the same value can be input
using [ 2nd ] [
;
]. For example, to input the data 40 and 55 ten times,
press 40 [
,
] 55 [ 2nd ] [
;
] 10 [ DT ].
• The values of the statistical variables depend on the data you input. You
can recall them by the key operations shown in the below table. To
predict a value for x (or y) given a value for y (or x), enter the given
value, press [ 2nd ] [
∧
y
] (or [ 2nd ] [
∧
x
] ), and press [ = ] again. See
Example 42~43.
Y
X
0
• P( x, y )
x
y
• P( r,
θ
)
0
X
θ
r
Y