# Ap Statistics: Formulas And Tables

AP Statistics: FORMULAS AND TABLES
(II)
Probability
(III)
Inferential Statistics
(I) Descriptive Statistics
x
Standardized
statistic – parameter
P(A
B) = P(A) + P(B) – P(A
B)
i
x =
test statistic:
standard deviation of statistic
n
P(A
B)
P(A B) =
Confidence interval:
P(B)
1
statistic ± (critical value) • (standard deviation of statistic)
2
s =
(x – x )
x
i
n – 1
Single-Sample
E(X) =
=
x p
x
i
i
Standard Deviation
2
2
(n – 1)s + (n – 1)s
Statistic
2
2
(
)
1
1
2
2
Var(X) =
=
x –
p
s =
of Statistic
x
i
x
i
p
(n – 1) + (n – 1)
1
2
Sample Mean
n
If X has a binom ial distribution with param eters
y ˆ = b + b x
0
1
n and p, then:
p(1 – p)
Sample Proportion
n
n
(x – x )(y – y )
k
n – k
P(X = k) =
p (1 – p)
i
i
b =
k
1
2
(x – x )
i
Two-Sample
= np
x
Standard Deviation
b = y – b x
Statistic
of Statistic
0
1
=
np(1 – p)
x
2
2
1
2
+
= p
1
x – x
y – y
Difference of
n
n
p ˆ
i
i
r =
1
2
sample means
n – 1
s
s
x
y
p(1 – p)
Special case when
=
1
2
=
p ˆ
n
1
1
s
+
y
b = r
n
n
1
1
2
s
x
If x is the m ean of a random sam ple of size n
p (1 – p )
p (1 – p )
1
1
2
2
+
2
Difference of
(y – y ˆ )
from an infinite population with m ean
and
n
n
i
i
1
2
sample proportions
=
n – 2
standard deviation , then:
2
Special case when p = p
(x – x )
1
2
i
1
1
p(1 – p)
+
n
n
1
2
2
(observed – expected)
Chi-square test statistic =
expected