Stats - Probability
Pearson Edexcel Mathematics 2022
Probability basics
What two forms do you give answers to probability questions?
- Decimals
- Fractions
In terms of probability, what is an experiment?
A repeatable process that gives rise to a number of outcomes.
Mutually exclusive and independent events
What does it mean for two events to be mutually exclusive?
The two events can’t happen at the same time.
If $A$ and $B$ are mutually exclusive, what is $P(A \text{and} B)$?
If $A$ and $B$ are mutually exclusive, what is $P(A \text{or} B)$?
What would the Venn diagram look like for two mutually exclusive events, $A$ and $B$?
What does it mean if two events are independent?
One event happening does not affect the probability of the other happening.
If $A$ and $B$ are independent, what is the probability of $P(A\text{and}B)$?
How could you prove mathematically that two events $A$ and $B$ aren’t independent?
Show
\[P(A \text{and} B) \neq P(A)\times P(B)\]Phrasing complementary outcomes
In an experiment calculating the percentage of left-handed people, what would you say instead of right-handed?
Not left handed.