Probability_Flashcards__Q_A_Only_

Question 1

What is the addition of probability formula for mutually exclusive events?

Answer 1

P(A ∪ B) = P(A) + P(B)

Question 2

What is the addition of probability formula for non disjoint?

Answer 2

P(A ∪ B) = P(A) + P(B) - P(A ∩ B)

Question 3

What is the general formula for addition rule?

Answer 3

P(A or B) = P(A) + P(B) - P(A and B)

Question 4

What is the multiplication of probability formula for independent events?

Answer 4

P(A ∩ B) = P(A) × P(B)

Question 5

What is the (a and b) formula for dependent events?

Answer 5

P(A and B) = P(A) × P(B|A)

Question 6

What is the formula for conditional probability?

Answer 6

P(B|A) = P(A and B) / P(A)

Question 7

What is a key property of mutually exclusive events?

Answer 7

P(A ∩ B) = 0

Question 8

When are two events independent?

Answer 8

P(A|B) = P(A) and P(B|A) = P(B)

Question 9

What is the formula for relative risk? Stats

Answer 9

RR = P(A|B) / P(A|Bc)

Question 10

What do contingency tables summarize?

Answer 10

Relationships between two categorical variables

Question 11

What is the purpose of probability trees?

Answer 11

To visualize sequences of events and their probabilities

Question 12

What do Venn diagrams show?

Answer 12

Relationships between events, including overlaps. 2 circles, if they are not overlapping then they are disjoint, no pr of them happening at once

Question 13

What is a common mistake in probability calculations?

Answer 13

Forgetting to subtract overlaps in the addition rule

Question 14

Is conditional probability symmetric?

Answer 14

No, P(A|B) ≠ P(B|A)

Question 15

What is the probability of an event not occurring?

Answer 15

P(A’) = 1 - P(A)

Question 16

How do we find the probability of 1st class given survival?

Answer 16

Restrict attention to survivors and find the fraction in 1st class

Question 17

How does smoking affect lung cancer probability?

Answer 17

P(C|S) = 0.53, P(C|S’) = 0.13

Question 18

What is the probability that a car is not made in the US?

Answer 18

P = 1 - 0.4 = 0.6

Question 19

How is the probability of success calculated?

Answer 19

Weighted sum of probabilities across categories

Question 20

Are independent and disjoint events the same?

Answer 20

No, independent events can co-occur; disjoint events cannot

Question 21

What visual tools help solve probability problems?

Answer 21

Probability trees and Venn diagrams

Question 22

What does a probability tree show?

Answer 22

Branching probabilities of sequences of events

Question 23

When should you use P(A ∩ B) = P(A) × P(B|A)?

Answer 23

When events are dependent

Question 24

What is the probability of rolling two heads in two coin flips?

Answer 24

P = 0.5 × 0.5 = 0.25