GEOG 3MB3 Lecture Notes - Lecture 7: Mutual Exclusivity, Lightning
28 May 2018
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October 4, 2016
Odds and Probability
- People have been playing with the idea of probability for a long time (as can be
seen with these ancient Roman dice)
- There are striking examples of failure to understand probability that you can find
online
What’s the probability?
- The probability for getting heads or tails does not change on successive coin
flips, the probability of getting heads or tails is always the same
- In practice people might think the probability will change but it really does not
Probability
- Probability is between 0 and 1
- 1 means it is guaranteed to happen 0 means it is guaranteed to not happen
- Which sequence of numbers in lotto 6/49 is more likely? Both are equally likely
(this does not intuitively make sense)
Probability of…
- 1/28 000 is not accurate of our probability of dying in Canada from a car accident
because we are young. Our probability of death is even higher if we are a young
man
Calculating P()
- In the case of dice this is pretty easy to understand
- Dice are not perfectly engineered so the actual probability is not actually 0.167,
but no one can calculate the actual probability so we can use them in random
games of chance
Calculating P() in the real world
- It can be hard to find the denominator in the example of getting struck by
lightning because it can depend on our lifestyles, where we live etc
Disjoint (mutually exclusive) events
- 2 things are mutually exclusive if they cannot occur at the same time
- For instance, you cannot role a 1 and a 5 on the same die at the same time so
these are mutually exclusive events
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
People have been playing with the idea of probability for a long time (as can be seen with these ancient roman dice) There are striking examples of failure to understand probability that you can nd online. The probability for getting heads or tails does not change on successive coin. Ips, the probability of getting heads or tails is always the same. In practice people might think the probability will change but it really does not. 1 means it is guaranteed to happen 0 means it is guaranteed to not happen. Both are equally likely (this does not intuitively make sense) 1/28 000 is not accurate of our probability of dying in canada from a car accident because we are young. Our probability of death is even higher if we are a young man. In the case of dice this is pretty easy to understand.
