Unit 5

Question 1

Probability

Answer 1

If I do (this) many times, (this thing will happen) about (%) of the time

Question 2

Sample space

Answer 2

set of all possible outcomes or “events”

Question 3

Golden Rule

Answer 3

*Use if all outcomes are equally likely

of possible successes/# of possible outcomes

For EX: getting a 3 on a fair die, 1/6

Question 4

0-1 Rule

Answer 4

• “Any probability is a number between 0 and 1”
• 0 -> never occurs
• 1 -> always occurs

Question 5

100% Rule

Answer 5

• “The sum of the probability of all possible outcomes must equal 1”

Question 6

Complement Rule

Answer 6

• Probability that A does NOT occur is 1 - P(A), “complement” of A
• “At least” “more than”
• 1 - (don’t want)

Question 7

Addition Rule

Answer 7

• A OR B -> Sum of probabilities - overlap
• OR = +

Question 8

Multiplication Rule

Answer 8

• A AND B -> product of probability of A and B, GIVEN THAT A HAS ALREADY HAPPENED
• So… P(A and B) = P(A) * P(B | A)
• When not given “and then” you have to do it twice, switch order
  –> If independent: P(A and B) = P(A) * P(B)

Question 9

Independent

Answer 9

The two events are independent if whether one occurs does NOT change the probability of the other occuring:

P(A) = P(A | B) –> Both(and)/B

• If it doesn’t change = independent, if it DOES change = NOT independent

Question 10

Disjoint

Answer 10

Two events are disjoint (“mutually exclusive” if they have no outcomes in common

EX:
Disjoint - drawing a jack OR a queen
Not disjoint - Drawing a jack and a queen

** Use a brief sentence