Test 2 Practice Test #31. Identify which of the following choices is the appropriate description of the statistic listed. It is possible to use achoice more than once.(A) A measure of center that is not resistant to outliers.(B) A measure of center that is resistant to outliers.(C) A measure of spread that is not resistant to outliers.(D) A measure of spread that is resistant to outliers________ Interquartile range________ Mean________ Median________ Range________ Standard deviation______ 2. Which of the following is a graphical procedure for displaying quantitative data?(A) Stem-and-leaf plot (B) Histogram (C) Box plot (D) All of (A), (B) and (C) (E) None of (A), (B) and (C)______ 3. Anita and Joel are each given the same set of data and are asked to construct a histogram. They agree touse exactly the same class intervals; Anita constructs a frequency histogram and Joel constructs a relativefrequency histogram. TRUE or FALSE: Anita’s frequency histogram and Joel’s relative frequencyhistogram will look the same, except for the labeling of the vertical axis.Often people invite their family, friends, colleagues and other associates to their birthday parties but ask that they notpurchase a gift. In most cases these people purchase a card, but not a gift, while close family members will stillpurchase a gift. The data below reflect the amount of money spent on birthday cards and gifts for a random sample of100 people attending birthday parties. Use this boxplot to answer questions 4 through 6. x----- ------------------------------x • •------------------------------------------------------------------------------------------------------------------------------------------0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40Money Spent on Cards and Gifts______ 4. Which of the following best describes the center of this distribution?(A) The distribution has outliers at 24 and 40.(B) The range of the data is 40 – 0 = 40.(C) The mean of the data is 4.(D) The median of the data is 4.(E) The median of the data is 18.______ 5. Which of the following best describes the spread of this distribution?(A) The interquartile range of the data is 10 – 2 = 8.(B) The median of the data is 4.(C) The range of the data is 18 – 0 = 18.(D) The range of the data is 10 – 2 = 8.(E) The interquartile range of the data is 18 – 0 = 18.______ 6. Which of the following best describes the shape of this distribution?(A) The distribution is trimodal.(B) The distribution has outliers at 24 and 40.(C) The distribution is symmetrical.(D) The distribution is skewed to the left.(E) The distribution is skewed to the right.On February 11, 2012 Joel celebrated his birthday at Bailey’s Pub and Grill. Below are the ages of the 11 people inattendance at the birthday meal. Use this data to answer questions 7 through 11. Please write your final answer on theline before the question number. You can use the calculator, or you can choose to do the problems by hand, inwhich case any work you show will be considered for partial credit.12 55 38 50 40 39 46 48 53 41 40__________ 7. Calculate the mean of the data.__________ 8. Calculate the median of the data.__________ 9. Calculate the range of the data.__________ 10. Calculate the standard deviation of the data.__________ 11. Calculate the interquartile range of the data._____ 12. To estimate the mean age of all students attending her university, a statistician selected a simple randomsample of 9 students. Prior to going on vacation, the statistician collected data for only 7 of the 9 students,and determined that the median age of the 7 students was 24 years. The statistician took the data with heron vacation, so this median value of 24 is all you know about the ages of those 7 students. You do,however, now know that the last two students were 18 and 36 years of age, respectively. Based on thisinformation, which of the following best describes the median age of all 9 students in the sample?(A) 24.67 (B) 24 (C) 26 (D) 27 (E) Cannot be determined from the information provided13. On January 25, 2012 Anita celebrated her birthday, and on February 11, 2012 Joel celebrated his birthday. BothAnita and Joel went out with their family and friends to celebrate their birthdays. Below are the ages of the 23people in attendance at the two birthday meals. Construct an appropriate stem-and-leaf plot to graphically displaythis data.26 46 55 30 46 50 39 46 49 34 44 51 12 55 38 50 40 39 46 48 53 41 4014. Consider the stem-and-leaf plot constructed in question 13. Use the stem-and-leaf plot to completely describe thedistribution of the ages for this sample of 23 people attending the birthday meals.Test 2 Practice Test #3 Solutions1. D – Interquartile rangeA – MeanB – MedianC – RangeC – Standard deviation2. D – Stem-and-leaf plots, histograms, and boxplots all require quantitative data3. TRUE – The two histograms will look the same (see page 55)4. D – The line in the box represents the median 5. A – The IQR is 10 – 2 = 8 (the range would be 40 – 0 = 40)6. E – The outliers causes the distribution to be skewed to the right 7. ´X =∑xn=12+ 55+…+ 4011=46211=428. Median Location = n+12=11+12=122=6; Median = 6th ordered observation = 41 9. Range = Max – Min = 55 – 12 = 43 10. S = 11.576; see page 77 for how to compute S 11. Median of the 5 smallest observations = Q1 = 39Median of the 5 largest observations = Q3 = 50IQR = Q3 – Q1 = 50 – 39 = 1112. B – With n = 7, the median location = (n + 1)/2 = (7 + 1)/2 = 4, so the 4th ordered observation is themedian, 24.With the two values added, n = 9, so the median location = (9 + 1)/2 = 5 Since 18 is less than the median, 24 is now the 5th ordered observation and hence the medianremains unchanged at 24.13. 1. 2 1* 2.2* 63. 0, 43* 9, 8, 94. 4, 0, 1, 04* 6, 6, 6, 9, 6, 85. 0, 1, 0, 35* 5, 5 where 5 | 1 = 5114. The distribution is skewed to the left. The data ranges from 12 to 55, and the center is in the 40’s(Mean = 42.52, Median = 46). 12 would be considered an
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