Notation
n
sample size
N
population size
ˆ
p
sample proportion
p
population proportion
x
or
x
i
= single observation
summation notation
z=¿
z-score
( )P A
probability of A
M or
x
sample mean
population mean SS = Sum of Squares
d . f .=¿
degree of freedom
SD2 or
s2=¿
sample variance
σ2=¿
population variance
O
observed frequency
E=¿
expected frequency
SD or
s
sample stdev
population stdev SEM = standard error of the mean
Formulas
x
xn
2
2
( )
1
i
x x
sn
2
( )
1
i
x x
sn
z=´x−μ
(
σ
√
n
)
3 1
IQR Q Q
^
y=b0+b1x
x
N
2
2
( )
i
x
N
σ=
√
∑
(
xi−μ
)
2
N
x
z
Range=Max-Min
y−
^
y
Probability
( ) ( ) 1
c
P A P A
( )
( ) ( )
P A B
P A B P B
( ) ( ) ( )P A B P A P B
( ) 0P A B
Conditional Probability Two Independent Events Mutually Exclusive
( ) f
P E N
( ) ( ) ( ) ( )P Aor B P A P B P A B
( ) ( )E x x p x
2
( ) ( )x p x
!
! !
nn
rr n r
( ) (1 )
r n r
n
P X r p p
r
n p
(1 )n p p
Central Limit Theorem
Formula Sheet for Math 155 Statistical Reasoning
