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1 | |
When two fair six-sided die are tossed, what is the expected value of the sum of the faces? |
| | A) | 6 |
| | B) | 7 |
| | C) | 5 |
| | D) | 4 |
| | E) | 12 |
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2 | |
When two fair six-sided die are tossed, what is the probability of getting a sum greater than 6? |
| | A) | 1/2 |
| | B) | 1/6 |
| | C) | 7/12 |
| | D) | 13/18 |
| | E) | 5/18 |
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3 | |
Twenty-five percent of all households in a town have broadband Internet access. In a random sample of fifteen houses, what is the probability that exactly five have broadband Internet access? |
| | A) | 0.48 |
| | B) | 0.75 |
| | C) | 0.1651 |
| | D) | (0.25)5 |
| | E) | none of the above |
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4 | |
A fair coin is tossed five times. What is the probability that it lands tails up at least once? |
| | A) | 1/32 |
| | B) | 31/32 |
| | C) | 4/5 |
| | D) | (.5)4 (.5)1 |
| | E) | 5/32 |
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5 | |
In a uniform distribution, [1, 9], what is the probability that x will be greater than zero? |
| | A) | 1/2 |
| | B) | 1/8 |
| | C) | 0 |
| | D) | 1 |
| | E) | none of the above |
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6 | |
What is the probability that at least two cars will cross a given intersection in the next half hour, if crossings are poisson-distributed with an average of four cars per half-hour? |
| | A) | 0.9084 |
| | B) | 0.0916 |
| | C) | 0.1465 |
| | D) | 0.8535 |
| | E) | none of the above |
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7 | |
The daily temperature in Kodiak, Alaska has a uniform distribution with a range from -20 degrees to +10 degrees. What is the probability that the temperature is at least 5 degrees on any given day? |
| | A) | 5/6 |
| | B) | 1/2 |
| | C) | 1/6 |
| | D) | 1/3 |
| | E) | none of the above |
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8 | |
From a group of six men and four women, a committee of four is to be chosen. What is the probability that this committee consists of exactly two men and two women? |
| | A) | 1/10 |
| | B) | 5/7 |
| | C) | 1/14 |
| | D) | 3/7 |
| | E) | none of the above |
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9 | |
Given the following probability distribution
x P(x)
1 0.2
2 0.3
3 0.3
4 0.2
The variance of the random variable is: |
| | A) | 2.5 |
| | B) | 7.3 |
| | C) | 1.05 |
| | D) | 1.0246951 |
| | E) | 4.8 |
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10 | |
The probability that no typing errors will occur on a page is 0.05. The probability that one error will occur is 0.1; the probability of 2 errors is 0.1; 3 errors is 0.2; 4 errors is 0.2; 5 errors is 0.3; and the probability of 6 errors is 0.05. The average number of errors per page is: |
| | A) | 1.5 |
| | B) | 2.1 |
| | C) | 3.5 |
| | D) | 0.45 |
| | E) | none of the above |
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11 | |
If the variance of random variable X is greater than the variance of random variable Y, then: |
| | A) | the mean of X must be greater than the mean of Y. |
| | B) | the median of X must be equal to the median of Y. |
| | C) | the probability that X is equal to Y is zero. |
| | D) | the standard deviation of X is greater than the standard deviation of Y. |
| | E) | all of the above are true. |
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12 | |
A thoroughbred horse-racing facility has opened a drive-through wagering booth. Research has shown that the number of visitors to this booth will be Poisson-distributed an average arrival rate of 3 customers per hour. If a customer has just left this booth, what is the probability that one-half hour will elapse before the next customer's arrival? |
| | A) | 0.2231 |
| | B) | 0.4724 |
| | C) | 0.5276 |
| | D) | 0.7769 |
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