S1 Maths Formulas
Median Formula
(n+1)/2
LQ Formula
(n+1)/4
Mid-range Formula
(xmax+xmin)/2
Mean Formula
(∑x)/n
1 disadvantage of mean
Affected by extreme values
Range Formula
Largest - smallest value
1 disadvantage of median
May not be characteristic if the data is small
SD Outlier Method
Mean +/- 2SD
Independence Definition
Outcome of one event doesn't affect the other
P(A∩B) meaning
P(A) and P(B)
P(A∪B) meaning
P(A) or P(B)
Indep A given B Formula
P(AIB)=P(A)
Conditional Probability Formula
P(AIB)=P(A∩B)/P(B)
P(A∩B) Formula
P(A∩B) = P(A) + P(B) - P(A∪B)
P(A∪B) Formula
P(A∪B) = P(A) + P(B) - P(A∩B)
Why do np values work with Binomial Distribution?
The distribution is symmetrical
1 disadvantage of mode
There may be more than 1 mode
IQR Formula
UQ-LQ
1 advantage of median
Unaffected by extreme values
1 advantage of mode
Unaffected by extreme values
1 advantage of mean
Uses all data
E(X) symbol
µ
Var(X) symbol
σ^2
Var(X) Formula
∑(r^2)P(X=r)-(∑rP(X=r))^2
Sxx Formula (Bracket)
∑(x-mean)^2
Sxx Formula Frequency (Bracket)
∑(x-mean)^2f
Sxx Formula Frequency (Non-Bracket)
∑(x^2f)-n*mean^2
Mean of Frequency Formula
∑(xƒ)/n
E(X) Formula
∑rP(X=r)
Sxx Formula (Non-Bracket)
∑x^2-n*mean^2
Standard Deviation
√sxx/(n-1)
RMSD Formula
√sxx/n
Linear Coding, S.D
Sy=bSx
Histogram Formula (fd as focus)
fd=f/cw
Sample Variance
sxx/(n-1)
MSD Formula
sxx/n
Mutually Exclusive Definition
Events have no outcomes in common. One event excludes the other
P(A∩B) ME Formula
P(A∩B)=0
Indep non A given B Formula
P(A∩B)=P(A)xP(B)
P(A∪B) ME Formula
P(A∪B)=P(A)+P(B)
IQR Outlier Method
Quartile +/- 1.5*IQR
UQ Formula
3(n+1)/4
Linear Coding, Mean (pretend you have mean sign)
y=a+bx