Probability

Question 1

What does P(AnB) mean?

Answer 1

Probability both occuring

P(A) x P(B)

Question 2

What does P(AuB) mean?

Answer 2

Probability A or B or both occuring

Question 3

How to find P(AuB) tho?

Answer 3

P(A) + P(B) - P(AnB)

Question 4

P(A’) means whats

Answer 4

Probability A doesn’t occur

1 - P(A)

Question 5

P(B’) means what?

Answer 5

Probability B doesn’t occur

1 - P(B)

Question 6

• Provide more notes, this is too obscure.
• Add like questions and examples and what to be aware of n shi

Answer 6

Yaa

Question 7

Main part of this topic?

Answer 7

The venn diagram

Question 8

I mean from what i see, it’s just the typical fraction thing, with the total at the denominator and the remaining at the numerator n shi. My book too obscure bro

Answer 8

¯_(ツ)_/¯

Question 9

In a Venn diagram of P(A), P(B) Or P(AnB)

What does P(A) mean?

Answer 9

Probability of what’s within A specifically that’ll occur
So literally, EVERYTHING that’s in A even if it intersects

Question 10

In a Venn diagram of P(A), P(B) Or P(AnB)

What does does P(B) mean?

Answer 10

Probability of what’s within B specifically that’ll occur
So literally, EVERYTHING that’s in B even if it intersects

Question 11

In a Venn diagram of P(A), P(B) Or P(AnB)

What does P(A’) mean?

(Vice versa for P(B’))

Answer 11

Probability of what’s not within A specifically that’ll occur
So u get all the numbers outside of A, and don’t include the ones that intersect with A

Question 12

In a Venn diagram of P(A), P(B) Or P(AnB)

How would u find P(A’)?

(Vice versa for P(B’))

Answer 12

U do 1 minus P(A)
for example if P(A) = 0.8
P(A’) = 1 - 0.8 = 0.2

All probabilities are usually between 0 and 1

Question 13

In a Venn diagram of P(A), P(B) Or P(AnB)

What does P(A or B or both) mean?

IN DATA BOOKLET

Answer 13

P(AuB)
The issue is that, following the way of understanding P(A) and P(B)
Technically, we have the intersection twice therefore we have the formula:
P(AuB) = P(A) + P(B) - P(AnB)

Question 14

In a Venn diagram of P(A), P(B) Or P(AnB)

What does P(A and B) mean then?

Answer 14

Intersection of P(A) and P(B) specifically (not including just the A or B, if u know u know)
Course, hoping that the question given we may have the intersection
In addition, will help for finding P(AuB)

Question 15

In a Venn diagram of P(A), P(B) Or P(AnB)

How would u find P(AuB)?

Answer 15

So all numbers within A, within B and within intersection of A and B

Question 16

In a Venn diagram of P(A), P(B) Or P(AnB)

How would u find P(AnB)?

Answer 16

Only within intersection of P(A) and P(B)

Question 17

What does independent mean?
(A and B are independent)

NOT IN DATA BOOKLET

Answer 17

A does not affect the likelihood of B happening and vice versa
So in terms of Venn diagram, they can intersect
and in addition, a formula:
P(AnB) = P(A) x P(B)

Question 18

What does mutually exclusive mean
(A and B are mutually exclusive)

Answer 18

When A cannot happen at the same time as B
Therefore in a supposed Venn diagram, they wouldn’t intersect
in addition, ya use the formula:
P(AnB) = P(A) x P(B) and must equal zero
so!
P(AnB) = 0, that makes sense ¬.¬

Question 19

How to find if it’s independent?

Answer 19

Say u do actually have a number within intersection
X the numbers within circles (although they may intersect, remember what P(A) means, everything within that circle)
IF it doesn’t equal the intersect, it is not independent
P(AnB) = P(A) x P(B)

Question 20

How about probability with replacement?

Four cards from a regular pack of 52 playing cards are picked randomly from the deck. Find the probability that all four are aces…

Answer 20

4/52 x 4/52 x 4/52 x 4/52 = 256/7311616 = 1/28561

= 0.0000350 to 3sf

Question 21

How about probability without replacement?

Four cards from a regular pack of 52 playing cards are picked randomly from the deck. Find the probability that all four are aces…

Answer 21

4/52 x 3/51 x 2/50 x 1/49 = 24/6497400 = 1/270725

= 0.00000369 to 3sf (smaller than with replacement)

Question 22

How to use tree diagrams?

Answer 22

If only I can add pictures for free.

Sound super obscure but, gaining probability after the first probability is done. There can be multiple after the first one. In addition, be aware what they ask for the question. There’s a possibility that even after u got ur answer, u may have to x it multiple times to gain the true answer

(the true if u know, u know)

Question 23

Do ya know about two way tables???

Answer 23

¯_(ツ)_/¯

Question 24

If it’s mutually exclusive, what it mean for P(AuB)?

Answer 24

P(AuB) = P(A) + P(B)
There’s no P(AnB) cuz it’s zero