1
Q
expected value
A
the average value of a chance process, after repeating many, many trials
2
Q
E(X)=
A
sum of X*P(X)
3
Q
expected value is the same as…
A
mean
4
Q
st dev=
A
root of (sum of (X-mean)^2*P(X))
5
Q
+/- by an RV by a constant…
A
center (mean) +/- by that constant, spread (st dev) stays the same, shape stays the same
6
Q
x// an RV by a constant…
A
mean x// by the constant
st dev x// by the constant
variance x// by the constant
shape stays the same
7
Q
E(X+Y)=
A
E(X)+E(Y)
8
Q
st dev of X+Y
A
root of (st dev X^2+st dev Y^2)
9
Q
E(X-Y)
A
E(X)-E(Y)
10
Q
st dev of X-Y
A
root of (st dev X^2+st dev Y^2)
