Independent Events
whatever happened in the past is independent of future events
combine events by multiplication
e.g. chance of 2 heads (or 3 heads) in a row? .5 x .5 x (.5)
Mutually Exclusive
if A happened, B is not going to happen
combine events by addition/summation
e.g. chance of head or tail? .5 + .5 = 1
Non-mutually Exclusive
The overlapped area or area of intersection is there
substract that area; A + B - (AB)
E.g The chance of meeting someone who is obese, has diabetes, or both?
assume obesity prevalence = 30%, diabetes prevalence = 10%
30% i.e. 0.3 + 10% i.e. 0.1 - (0.3 x 0.1)
40% (0.4) - 3% (0.03) = 37% or 0.37
Central Limit Theorem (CLT):
the random sampling distribution of mean would always tend to be normal irrespective of the population distribution for which the sample were drown.
Standard error of the mean