final 26-50
42. A normal distribution has a mean equal to 53. What is the standard deviation of this normal distribution if 2.5% of the proportion under the curve lies to the right of x = 66.72? (Round your answer to two decimal places)
A) -7.00 B) 0.14 C) 7.00 D) 49.00
34. The probability of making zero to two errors per 1,000 keystrokes is 0.43, and the probability of making three to five errors per 1,000 keystrokes is 0.28. Find the probability (per 1,000 keystrokes) associated with making at most five errors.
A) .29 B) .43 C) .57 D) .71
36. The standard normal distribution is normally distributed with a mean of ____ and a variance of ____.
A) 0; 1 B) 1; 0 C) any value; any positive value D) any positive value; any value
39. What is the z score for scores in the bottom 5%?
A) 1.645 B) -1.645 C) .4801 D) -0.050
26. A researcher determines that the probability of missing class among students at a local school is p = .16. Assuming that the school has 300 students enrolled, how many students can we expect to miss class on a given day? Hint: This is a binomial probability distribution.
A) 252 students B) 48 students C) 16 students D) There is not enough information to answer this question.
38. A researcher wants to know the probability of being named on the honor roll from a population where 8% of students are on the honor roll. If the researcher selects a sample of 400 students, then what is the mean number of students expected to be on the honor roll? Hint: This is a binomial distribution, where p = 0.08 and q = 0.92.
A) 29 B) 32 C) 368 D) 200
27. If the standard deviation of a probability distribution is 9, then the variance is
A) 3 B) 9 C) 81 D) unknown
40. Which proportion is largest in a z distribution?
A) The proportion of area above the mean. B) The proportion of area between z = +1 and z = -1. C) The proportion of area greater then z = 1.0. D) The proportion of area less than z = 0.
47. Suppose that a researcher selects a sample of participants from a population. If the shape of the distribution in this population is positively skewed, then what is the shape of the sampling distribution of sample means?
A) approximately positively skewed B) approximately negatively skewed C) approximately normally distributed D) There is not enough information to answer this question, because the population mean and variance are not given.
41. Scores far from the mean are located in the ________ of a normal distribution.
A) body B) tails C) most sensitive areas D) most uncertain areas
33. Bayes' theorem is often applied to a variety of ________ probability situations, including those related to statistical inference.
A) generic B) absolute C) conditional D) fixed
44. Each of the following statements are true, except that
A) increasing the sample size will decrease standard error B) the larger the sample size, the larger the standard error C) the larger the standard deviation in the population, the larger the standard error D) both B and C
46. A researcher selects a sample of 16 participants from a population with a variance of 4. What is the standard error of the mean?
A) less than 1 (square root of the variance aka standard dev divided by the sqrt of N) B) equal to 1 C) greater than 1 D) There is not enough information to answer this question.
28. When the probability of one outcome changes depending on the occurrence of a second outcome, these outcomes are referred to as
A) mutually exclusive B) complementary C) independent D) conditional
30. The following distribution most closely approximates
A) normal distribution B) positively skewed distribution C) negatively skewed distribution D) multimodal distribution
45. Regardless of the shape of the distribution in the population, the sampling distribution of sample variances approximates a
A) normal distribution B) positively skewed distribution C) negatively skewed distribution D) multimodal distribution
29. The probability of a college student being employed is p = .35. The probability of a student being employed and dropping out of college is p = .20. Hence, the probability of a student dropping out of college, given that he or she is employed, is
A) p = .07 B) p = .57 C) p = .55 D) There is not enough information to answer this question.
49. What values are distributed along the x-axis for a sampling distribution of the sample mean?
A) scores B) sample means C) sample variances D) both B and C
50. What values are distributed along the x-axis for a sampling distribution of the sample variance?
A) scores B) sample means C) sample variances D) both B and C
35. The normal distribution is symmetrical, which means that
A) scores above the mean are distributed the same as scores below the mean B) extreme scores are possible in a normal distribution C) there are an infinite number of possible normal distributions D) this characteristic has no practical implication
37. The unit of measurement distributed along the x-axis of a standard normal distribution is referred to as a
A) standardized score B) x-score C) normalized deviation D) z score
32. What is the implication for the tails of a normal distribution being asymptotic?
A) that scores above the mean are distributed the same as scores below the mean B) that extreme scores are possible in a normal distribution C) that there are an infinite number of possible normal distributions D) that this characteristic has no practical implication
31. The normal distribution has all of the following characteristics, except
A) the mean can be any number B) it is mathematically defined C) the total area under the curve is greater than 1.0 D) the mean, median, and mode are equal
48. For the experimental sampling strategy,
A) the order in which a participant is selected matters B) sampling is with replacement C) sampling is without replacement D) participants are not sampled from the population, but instead are sampled from other samples already drawn
43. How is the standard error of the mean typically reported in a graph?
A) using error bars B) by plotting sample means C) by listing group names along the x-axis D) it is never reported in a graph
