Bluman A.G. Elementary Statistics- A Step By Step Approach

Review Exercises 173Formula for the cumulative percentage:Cumulative % Formula for the percentile rank of a value X:Percentile cumulativefrequency 100nnumber of valuesbelow X 0.5total numberof values 100Formula for finding a value corresponding to a givenpercentile:c n • p100Formula for interquartile range:IQR Q 3 Q 1Review Exercises1. Net Worth of Wealthy People The net worth (inbillions of dollars) of a sample of the richest people inthe United States is shown. Find the mean, median,mode, midrange, variance, and standard deviation forthe data. (3–1) (3–2)59 52 28 26 1919 18 17 17 17Source: Forbes Magazine.2. Shark Attacks The number of shark attacks anddeaths over a recent 5-year period is shown. Find themean, median, mode, midrange, variance, and standarddeviation for the data. Which data set is more variable?(3–1) (3–2)Attacks 71 64 61 65 57Deaths 1 4 4 7 43. Battery Lives Twelve batteries were tested to see howmany hours they would last. The frequency distributionis shown here.Hours Frequency1–3 14–6 47–9 510–12 113–15 1Find each of these. (3–1) (3–2)a. Mean 7.3 c. Variance 10.0b. Modal class 7–9 d. Standard deviation 3.24. SAT Scores The mean SAT math scores forselected states are represented below. Find the meanclass, modal class, variance, and standard deviation, andcomment on the shape of the data. (3–1) (3–2)ScoreFrequency478–504 4505–531 6532–558 2559–585 2586–612 2Source: World Almanac.5. Rise in Tides Shown here is a frequency distributionfor the rise in tides at 30 selected locations in the UnitedStates.Rise in tides (inches) Frequency12.5–27.5 627.5–42.5 342.5–57.5 557.5–72.5 872.5–87.5 687.5–102.5 2Find each of these. (3–1) (3–2)a. Mean 55.5 c. Variance 566.1b. Modal class 57.5–72.5 d. Standard deviation 23.86. Fuel Capacity The fuel capacity in gallons of 50randomly selected cars is shown here.Class Frequency10–12 613–15 416–18 1419–21 1522–24 825–27 228–30 150Find each of these. (3–1) (3–2)a. Mean 18.5 c. Variance 17.7b. Modal class 19–21 d. Standard deviation 4.23–71