CHAPTER 4 Name

20. The mean of this distribution (don't try to find it) is certainly(a) very close to the median.(b) clearly less than the median.(c) clearly greater than the median. (d) can't say because the mean is random.21. Based on the shape of this distribution, what numerical measures would best describe it?(a) the five-number summary.(b) the mean and standard deviation.(c) the mean and the quartiles.(d) the mean and the correlation coefficient.22. To display the distribution of the lengths in inches of a sample of brook trout, you could use(a) a stemplot. (b) a pie chart. (c) a line plot.(d) Either (a) or (b). (e) Any of (a), (b), or (c).23. Which of these is not true of the mean of the lengths in inches of a sample of brook trout?(a) must take a value greater than 0.(b)(c)is measured in inches.would not change if we measured these trout in centimeters instead of inches.(d) Both (b) and (c).(e) Both (a) and (c).24. Which of these is not true of the standard deviation s of the lengths in inches of a sample of brook trout?(a) s must take a value between -1 and 1.(b) s is measured in inches.(c) s would not change if we measured these trout in centimeters instead of inches.(d) Both (b) and (c).(e) Both (a) and (c).25. A stemplot is(a) the same as a boxplot(b) a part of a small tree(c) a picture of a distribution(d) the same as a histogram(e) useful for describing categorical variables26. An outlier will usually have a large effect on the(a) first quartile (b) mean (c) third quartile (d) median (e) sample size27. Fifty percent of the observations will be at or above the(a) maximum (b) mean (c) median (d) third quartile28. For a distribution that is skewed to the left, usually(a) the mean will be larger than the median(b) the median will be larger than the mean(c) the first quartile will be larger than the third quartile(d) the standard deviation will be negative(e) the minimum will be larger than the maximum

29. Here is a set of data: 1300, 18, 25, 19, -7, 24. Which observation is the outlier?(a) 1300 (b) 25 (c) 19 (d) -7 (e) 2430. The five numbers in the five-number summary are(a) the five smallest observations(b) the five largest observations(c) the mean, the median, the maximum, the standard deviation and the sample size(d) x1, x2, x3, x4, and x5.(e) the median, the quartiles, the minimum and the maximum31. You have calculated that the value of the standard deviation for a set of data is -2.5. You can conclude that(a) the data are skewed to the left(b) the data are skewed to the right(c) there is very little variation in the data(d) all of the observations in the data set are negative(e) you made an error in your calculations32. One of the following 12 scores84 76 92 92 88 96 68 80 92 88 76 96was omitted from the stemplot below:The missing number is(a) 76 (b) 88 (c) 92 (d) 96 (e) 2226633. You calculate that the standard deviation of a set of observations is 0. This tells you that(a) you made an arithmetic mistake.(b) all the observations have the same value.(c) there is no straight-line association.(d) the mean must also be 0.(e) Both (b) and (d) are true.34. The standard deviation is a measure of(a) the center of a distribution.(b) the validity of a measurement.(c) the strength of a straight-line relationship.(d) the spread or variability of a distribution.(e) the most common value in a set of data.

35. You are giving a talk about the decay of the American family. You want to show by a graph how the numberof divorces has increased between 1970 and 2000. What type of graph should you draw?(a) A bar graph.(b) A boxplot.(c) A histogram.(d) A line graph.(e) A pie chart.36. You want to make a graph to display the distribution of the salaries of the 1500 professors at a largeuniversity. The best choice is(a) a boxplot.(b) a histogram.(c) a line plot.(d) a pie chart.(e) a stemplot.37. When dealing with financial data (such as salaries or lawsuit settlements), we often find that the shape of thedistribution is ________ . When the distribution has this shape, the ________ is pulled toward the long tail ofthe distribution, but the _______ is less affected. The sequence of words to correctly complete this statement is:(a) right skewed, median, mean.(b) left skewed, mean, median.(c) right skewed, mean, standard deviation.(d) right skewed, mean, median.(e) roughly symmetric, mean, correlation.38. Your score on the statistics final exam is at the 70th percentile of the scores for the class. Your score lies(a) below the lower quartile.(b) between the lower quartile and the median.(c) between the median and the third quartile.(d) above the third quartile.(e) Can't tell which quarter your score lies in.39. For categorical variables (like a person's occupation or sex) it only makes sense to speak of________ . It makes no sense to speak of the ________ or the ________ sex. The sequence of words tocorrectly complete this statement is(a) mean, standardized, median(b) median, mean, standard deviation(c) standard deviation, mean, median(d) counts or percents, mean, median40. What is the first quartile of the observations 2, -2, 1, -1, 1, 0, 0, 3, 0, 2, 3?(a) -1 (b) 0 (c) 1 (d) 2

41. A survey of people who invest in mutual funds found that "average" amounts invested were $18,200 and$43,500. One of these numbers is the mean amount invested and one is the median.(a) $43,500 is the mean, because a few people with very large amounts invested pull up the mean but not themedian.(b) $43,500 is the median, because a few people with very large amounts invested pull up the median but notthe mean.(c) $43,500 is the mean, because the mean must always be at least as large as the median.(d) $43,500 is the median, because the distribution of amounts invested is skewed to the right.42. You measure the length in centimeters and the weight in grams of each of a litter of newly hatchedrattlesnakes. The standard deviation of the weights is measured in(a) grams(b) centimeters(c) grams squared(d) no units -- it's a pure number43. If a bar graph is to be accurate, it is essential that(a) the bars touch each other.(b) the bars be drawn vertically.(c) both horizontal and vertical scales be clearly marked in equal units.(d) the bars all have the same width.(e) the explanatory variable be plotted on the horizontal axis.44. The mean and the median of a distribution are measures of(a) the number of observations(b) association(c) variability or spread(d) center45. The 70th percentile of a distribution is(a) the number with 70% of the data below it(b) the number with 70% of the data above it(c) the number that is 70% of the average(d) 70% of the sample size46. If 30 is added to every number on a list, the only one of the following that is not changed is(a) the mean(b) the mode(c) the 75th percentile(d) the median(e) the standard deviation

The five-number summary for scores on a statistics exam is 11, 35, 61, 70, 79. In all, 380students took the test. The next three questions concern this distribution.47. About how many students had scores between 35 and 61?(a) 35 (b) 61 (c) 95 (d) 190 (e) 28548. What does the five-number summary suggest about the skewness of the distribution of scores?(a) Skewed to the left(b) Skewed to the right(c) Not skewed(d) Nothing49. For the distribution of 380 exam scores,(a) the mean is very likely to be greater than the median.(b) the median is very likely to be greater than the mean.(c) the mean and the median are probably about equal.(d) we have no indication of whether the mean is larger than, smaller than, or equal to the median.Consider the following data on college enrollment by field of study and the sex of the students, from around1970:The next three questions refer to these data.50. About what percent of all female college students were enrolled in liberal arts and journalism?(a) 5% (b) 6% (c) 16% (d) 49% (e) 51%51. About how many college students were studying engineering?(a) 524 (b) 534 (c) 53,400 (d) 524,000 (e) 534,00052. What percent of college students were studying engineering?(a) 0.5% (b) 5% (c) 11% (d) 17% (e) 28%