Casio fx-260 User Manual

— 31 —
n!
(nr)!
n!
n!(nr)!
Permutation
•Input range: n  r  0 (n, r : integers)
•Formula: nPr 
Combination
•Input range: n  r  0 (n, r : integers)
•Formula: nCr 
Population Standard Deviation

n 
n

i  1
n
(xi – x)
2

n

x
2
– (x)
2
/ n
Sample Standard Deviation

n – 1 
n – 1

i  1
n
(xi – x)
2


x
2
– (x)
2
/ n
n – 1
Arithmetic Mean
o 
n

i  1
n
xi


x
n

Casio fx-260 Specifications

General

Type	Scientific
Display	10-digit LCD
Power Source	Solar
Approved for Exams	Yes, permitted for use on SAT, ACT, and AP exams
Battery Life	N/A (Solar-powered)