Flashcards
probability
Cards in this deck (10)
- 1what is 1/8 as a decimal fraction0.125
- 2Which of these numbers cannot be a probability? a) -0.00001 b) 0.5 c) 1.001 d) 0 e) 1 f) 20%a) and c)
probabilities are between 0 and 1 - 3If you toss a coin ten times, how many possible outcomes are there?2^10 = 1024
- 4how many coins do you have to toss before the probability of throwing 'all the same' (heads or tails) falls below 5%?the sequence goes
one toss 1/1 = 1
two toss 1/2 = 0.5
three toss 1/4 = 0.25
four toss 1/8 = 0.125
five toss 1/16 = 0.062
six toss 1/32 = 0.031
answer: 6 coins because 0.031 is smaller than 0.05
to do this on a calculator use trial and error:
2^6 = 64
2/64 = 0.031 - 5If you roll four dice, what is the probability of obtaining four numbers that are the same?workings out:
1) find 6^4 because there are 6 possible outcomes and 4 dice are rolled. answer = 1296
2) so there are 6 possible correct roles so 6/1296 = 0.0046.
slightly less than 5 in a thousand - 6true or false: a massive difference in sample data is likely to produce a probability close to 1false:
a massive difference produces a probability close to 0.
data that are close to eachother produces a probability close to 1 - 7what is the probability of rolling two dice and obtaining two numbers that are the same?36 possible outcomes (6x6)
there are 6 ways of producing two numbers the same (the six faces of the dice), so the answer is 6 in 36 or 1 in 6 - 8In a multiple-choice examination where there are five possible answers for each question, what is the probability of scoring four out of four correct purely by chance?5^4 = 625
this is LESS THAN 1 in 500 - 9you have asked a random sample of ten people the same question and all of them answered yes rather than no. What are the chances of obtaining a ratio of ten to zero simply by chance? About one in ten About one in a hundred Slightly more than one in a thousand Slightly less than one in a thousand Less than one in ten thousandmethod:
1) 2^10 = 1024
the answer is slightly LESS than one in a thousand. The chances of something happening one in 1024 times is less than the chances of something happening one in a thousand times. - 10There is clearly an extremely high possibility that the difference is just luck so the p-value must be close to _____?one
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- GEG 100 Flashcards on probability, created by Tyde D on 11/12/2018.
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- Tyde D
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