Final

1. What does the sum of the frequencies for all classes always equal? the class width ? the number of classes ? one ? the total number of observations in the data set ? 2. A politician who is running for office in a province with 3 million registered voters commissions a survey. In the survey, 5500 of the 10,000 registered voters interviewed say they plan to vote for her. Which of the following is the population of interest? the 5500 voters interviewed who plan to vote for her ? the 3 million registered voters in the province ? the 10,000 registered voters interviewed ? the 4500 voters interviewed who plan not to vote for her ? 3. Which of the following numbers constitutes the sum of the relative frequencies found in a relative frequency distribution for quantitative data? 2 ? 0 ? 1 ? 3 ? 4. Suppose you have 180 observations divided into classes. One of the classes has a data class frequency of 36. Which of the following would be its relative class frequency? 0.36 ? 0.18 ? 0.10 ? 0.20 ? 5. The average score for a class of 35 students was 70. The 20 male students in the class averaged 73. What was the average score for the 15 female students in the class? 73 ? 70 ? 66 ? 60 ? 6. According to Tchebysheff's Theorem, what is the percentage of measurements in a data set that will fall within three standard deviations of the mean? at least 68% ? 16% ? at least 89% ? 75% ? 7. The distribution of actual volumes of tomato soup in 450 mL cans is thought to be bell-shaped, with a mean of 450 mL and a standard deviation equal to 8 mL. Based on this information, between what two values could we expect 95% of all cans to contain? 434 and 466 mL ? 430 and 470 mL ? 432 and 468 mL ? 440 and 460 mL ? 8. A sample of 600 values produced the following summary statistics: Q = 35.6, Q ₁ ₂ = 54.2, Q = 62.4, and = 56.8. Given this information, which of the following ₃ x ̅ values constitutes the lower fence on a box plot? 102.60 ? 75.80 ?

26.80 ? −4.60 ? 9. Suppose that an experiment consists of tossing three unbiased coins simultaneously. How many simple events are contained in this experiment? 9 ? 3 ? 6 ? 8 ? 10. How many ways can one choose a combination of three items out of eight distinct items? 28 ? 112 ? 56 ? 224 ? 11. If P(A) = 0.80, P(B) = 0.70, and P(A B) = 0.90, then what is the value of P(A ∪ ∩ B)? 0.72 ? 0.56 ? 0.60 ? 0.63 ? 12. If P(A) = 0.30, P(B) = 0.40, and P(A ∩ B) = 0.20, what is the value of P(A/B)? 0.50 ? 0.67 ? 0.12 ? 0.08 ? 13. The probability distribution of the number of accidents in North York, Ontario, each day is given by |x |0 |1 |2 |3 |4 |5 | |P(x) |0.20 |0.15 |0.25 |0.15 |0.20 |0.05 | Based on this distribution, what would be the expected number of accidents on a given day? 4.62 ? 1.47 ? 1.81 ? 2.15 ? 14. The probability distribution of the number of accidents in North York, Ontario, each day is given in the table below: |x |0 |1 |2 |3 |4 |5 | |P(x) |0.20 |0.15 |0.25 |0.15 |0.20 |0.05 | Based on this distribution, what is the approximate value of the standard deviation of the number of accidents per day? 2.15 ? 1.53 ? 2.33 ? 6.95 ? 15. What is the standard deviation of a binomial distribution for which n = 50 and p = 0.15? 7.082 ? 6.375 ? 2.525 ?

50.15 ? 16. It has been alleged that 40% of all community college students favour Dell computers. If this were true, and we took a random sample of 25 students, the binomial probability table for cumulative values of x available in your text would reveal which of the following probabilities? (Select all that apply.) The probability of fewer than 19 students in favour is 1.000. ⬜ The probability of 10 or fewer students in favour is 0.586. ⬜ 17. If the random variable x is binomially distributed with n = 10 and p = 0.05, what is P(x = 2)? 0.55 ? 0.599 ? 0.075 ? 0.914 ? 18. A small community college in Ontario has four student organizations (A, B, C, and D). Organization A has 5 students, B has 8, C has 10, and D has 12. It is thought that new students have no preference for one of these organizations over the other. If seven new students are admitted to the college, what is the probability that one student will choose organization A, one will choose B, two will choose C, and three will choose D? approximately 0.059 ? approximately 0.243 ? 0.258 ? 0.200 ? 19. Given that Z is a standard normal random variable, what is P(−1.2 ≤ Z ≤ 1.5)? 0.5228 ? 0.4772 ? 0.3849 ? 0.8181 ? 20. If z is a standard normal random variable, what is the value of P(−1.25 ≤ z ≤ −0.75)? 0.6678 ? 0.1210 ? 0.2266 ? 0.1056 ? 21. If the random variable x is normally distributed with a mean of 88 and a standard deviation of 12, what is the value of P(x ≥ 96)? 0.2486 ? 0.2514 ? 0.4972 ? 0.1243 ? 22. Given a normal distribution with a mean of 80 and a standard deviation of 20, which z-score would correspond to an observation of x = 50? z = −1.5 ? z = +2.0 ? z = +1.5 ? z = +3.0 ? 23. The z-score of a random variable value of x = 2 is z = −2, while the standard deviation of the random variable x equals 2. What is the mean of x? 6 ? 2 ? 0 ?