AP Stats - 4b

Discrete random variables

Take on a countable number of values with gaps between

Continuous random variables

Infinite possible values with no gaps

Plus/minus a constant

Shape stays the same, center adds or subtracts a constant, spread stays the same

Multiply / divide by a constant

Shape stays the same, center multiplies or divides by a constant, spread multiplies or divides by a constant

Variance

Multiplies or divides by C^2

BINS

Binary, independent, number of fixed trials, same p for every trial

n / k

nCk

N

Number of trials

P

Prob of success

P(x=k) formula

nCk (p^{k}) \left(1-p\right)^{n-k}

binompdf

P(x=k)

Binomial mean

Np

Binomial standard deviation

\sqrt{np\left(1-p\right)}

Geometric mean

1/p

Geometric standard deviation

\frac{\sqrt{1-p}}{p}

binomcdf

Binomial P (X<K)

1 - binomcdf

Binomial P (X>K)

geometpdf

Geometric P (X=k)

geometcdf

Geometric P (X<k)

1 - geometcdf

Geometric P (X>k)