Midterm test review 2.0

Probability Review From Practice Test Mistakes

Standard deck

52 cards

Kings in a standard deck

4

Red cards in a standard deck

26

Probability of one king

4/52 equals = 1/13

Probability of one red card

26/52 = 1/2

Card probability formula

Favorable outcomes / total outcomes

Probability model

Lists each value of X with its probability

Discrete random variable

Counts outcomes

Until first success

Count failures before success

Success on first try

Success probability

Success on second try

Failure x success

Success on third try

Failure x failure x success

Four equal spinner sections

Success probability = 1/4

Not the desired section on four equal spinner

3/4

X = 1 on a spinner

A on first spin

X = 2 on a spinner

Not A then A

X = 3 on a spinner

Not A, not A then,A

Independent events

Multiply probabilities

Question asks until first success

Write a probability model

Common trap with probability models

Multiply failures before the first success

Memory trick

Failures first success last