Is a probability distribution defined if the only possible values of a random variable are 0, 1, 2, 3, and P(0) = P(1) = P(2) = P(3) = 0.25?
Yes. The sum of all probabilities is equal to 1. This is a uniform distribution
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There are 100 questions on a test with possible answers a-e and only one choice being correct for each question. What is the mean & S.D. of question a student could randomly answer correct on the test?
Mean: 20 Standard deviation = 4
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If boys and girls are equally likely, groups of 400 births have a mean of 200 girls and a standard deviation of 10 girls. Is 232 girls in 400 births an unusually high number?
Yes. The value given in higher than two standard deviations away from the mean.
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If boys and girls are equally likely, groups of 400 births have a mean of 200 girls and a standard deviation of 10 girls. Is 185 girls in 400 births an unusually low number?
No. The value is within two standard deviations of the mean.
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Does the table describe a probability distribution?
Yes. The sum of all probabilities is equal to 1
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What does the probability of 0+ indicate?
This means that there is a very low probability of an event occurring. Though improbable, the event is not impossible.
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What is the probability that at least 3 of the five flights arrive on time?
P(A) = 0.942
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In Ohio's Pick 4 game, you pay $1 to select a sequence of four digits, such as 7709. If you buy only one ticket and win, your prize is $5,000 and your net gain is $4,999. What is the expected value?
-50¢
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In Ohio's Pick 4 game, you pay $1 to select a sequence of four digits, such as 7709. If you buy only one ticket and win, your prize is $5,000 and your net gain is $4,999. If you buy 1 ticket, what is the probability of winning?
1 / 10,000 or 0.0001
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Find the mean and the standard deviation from the following probability distribution