Probability

Question 1

Are all probabilities between 1 and 0?

Answer 1

Yes

Impossible = 0
Unlikely = 0.25
Evens = 0.5
Likely = 0.75
Certain = 1

Question 2

Do probabilities add up to 1?

Answer 2

Yes

If you have multiple probabilities the sum of them is 1

Question 3

Sample Space Diagrams

Answer 3

One set of (numbers) across the top, one along the side. Use the (numbers) to follow the function of the sign in each box.

p(total n) = number of ways to score n / total number of outcomes

Question 4

Expected Frequency

Answer 4

probability x number of trials

Question 5

Relative Frequency

Answer 5

frequency / number of times you’ve tried the experiment

Question 6

Probability Tree Diagrams

Answer 6

Probability of each event on each branch.

Multiply along the branches to get total probability

Question 7

The ‘AND / OR’ rule

Answer 7

AND = both events happen
P(A and B) = P(A) x P(B)

OR = at least one event happens
P(A or B) = P(A) + P(B) = - P(A and B)

Question 8

Independent and dependent events

Answer 8

Independent = events happen separate to each other

Dependent = Each event depends on another