Statistics Midterm 2 Chapter 4-6 Of Triola

Front 1

event

Back 1

any collection (set) of outcomes of a random procedure (denoted with uppercase italicized letter, e.g. A)

Front 2

simple event

Back 2

consists of a single outcome

Front 3

sample space

Back 3

the set of all possible outcomes of random experiment (e.g. flip a coin, roll a die) (each element is an outcome)

Front 4

relative frequency (A)

Back 4

relative frequency (A) = # times a occurs/# of trials

Front 5

definition of probability

Back 5

Probability is the expected long-term relative frequency of an event (that is, the proportion of the time that we’d expect that particular event to occur in the long run).

Front 6

Approaches to get probability

Back 6

1) “classical” (theoretical)
When all outcomes in the sample space are equally likely P(A) = #(A) / #(S)
(coin toss, roll die A = {3, 4, 5, 6}, B = {1, 3, 5}, C = {1, 2, 3}, and D = {2, 4})
2) relative frequency (empirical)
3) subjective (personal)

Front 7

Law of Large Numbers (LLN)

Back 7

As a procedure is repeated again and again, the relative frequency probability of an event tends to approach the actual probability

Front 8

Prob of event P(A)

Back 8

0 <= P(A) => 1
P = 0 = A impossible
P = 1 = A certain

Front 9

Independent events

Back 9

Two events A and B are independent if the occurrence of one does not affect the probability of the other's occurrence.

Front 10

Dependent events

Back 10

If A occures it increases the prob of B occurring