PROBABILITY Flashcards
What is probability?
The likelihood of an event happening.
What is the the difference between theoretical and experimental probability?
theoretical is from thinking of all of the possibilities and doing it with math, experimental is the #successes/total attempts you observe.
how do you find “probability”
(# ways you can be successful) / (# total ways possible)
What is the symbol that joins two sets together into one set?
A big U , stands for UNION
What is the symbol that just takes the overlap of two sets?
An upside down U, look like this: ∩, INTERSECTION
What do students forget about OR ?
The OR BOTH part. The union of A and B are all of the elements in A, in B and also the ones that are in BOTH.
Why does OR go with UNION, ex. A U B = A or B
Because you are part of the union as long as you are a part of A or B or BOTH.
Why does AND go with INTERSECTION? A ∩ B = A and B
Because ONLY if you are a member of A and also a member of B, can you be a part of the intersection, A ∩ B
OR goes with______ [union or intersection]
union
AND goes with ______ [union or intersection]
intersection
UNION goes with ______ [OR or AND]
OR
INTERSECTION goes with _____ [OR or AND]
AND
What numbers can represent a probability?
Always between 0 and 1, examples: 0, .75, .05, 1, .35
What fractions can represent a probability?
Any fraction as long as the top is smaller than the bottom (or equal). IT CAN’T BE TOP HEAVY!
Can you have a probability of 3.5?
NO. probabilities are between 0 and 1
can you have a probability of 0.5?
Yes, that’s 50%
can you have a probability of 3/5?
Yes, that’s 60%
can you have a probability of 5/3?
NO… that is more than 1
How can you think of %
PER 100 (or, divided by 100)
If you have 3 pairs of shoes, two pairs of pants and 4 shirts.. how many outfits?
3*2*4= 24 outfits
How many cards in a deck of cards?
52
How many diamonds in a deck of cards?
13
What is the probability of randomly taking one card and getting a diamond from a deck?
13/52 or 1/4
What is the probability of randomly taking one card and getting a king from a deck?
4/52 or 1/13