Statistics Chapter 3

thank you emma gerber <3

Variance

the mean of the square of the distance each value of the data

variance equation

(n(Ex^2)-(Ex)^2)/(n^2)

standard deviation

the square root of the variance

Standard deviation equation (sample)

(n(Ex^2)-(Ex)^2)/n(n-1)

Empirical Rule

SHOULD happen- 1k=68%, 2k=95%, 99.7%

Chebysher's Theorem

MUST happen- (1+ 1/k²) \* 100%

Percentile equation

(B+1/2(E))/n

Outliers equation

Q3-Q1\=IQR

Equation for Lower Outlier Range

Q1-1.5(IQR)

Equation for Higher Outlier Range

Q3+1.5(IQR)

standard scores (or z) equation

z= (x-(mean))/standard deviation

Quartiles

Values that divide a data set into four equal parts

Parts of a Box and Whiskers

min, Q1, Median, Q3, max

Symbol for Variance

s²/σ^2

Symbol for Standard Deviation

s

CVariance Equation

s/(mean)