STAT303 Secs 509–511Spring 2001Exam #1Form AInstructor: Julie Hagen CarrollMay 2, 20011. Don’t EVEN open this until you are told to do so.2. Be sure to MARK your REGISTERED section number and your test form (A, B, C or D) on thescantron!3. Sign your name where indicated on your scantron and write your (Thursday) section number andcomputer number beside it. You may keep your exam.4. There are 20 multiple-choice questions on this exam, each worth 5 points. There is partial credit. Pleasemark your answers clearly on the scantron. Multiple marks will be counted wrong.5. You will have 60 minutes to finish this exam.6. If you are caught cheating or helping someone to cheat on this exam, you both will receive a grade ofzero on the exam. You must work alone.7. This exam is worth 100 points, and will constitute 20% of your final grade.8. Good luck!1STAT303 509–511 Exam #1, Form A Spring 20011. Which of the following is TRUE?A. ‘Number of roommates’ is a discrete nu-meric variable.B. ‘Test score on this exam’ is a continuousnumeric variable.C. ‘Number of days in a week’ is a discretenumeric variable.D. ‘Telephone number’ is a discrete numericvariable.E. All of the above are true.2. Which of the following affect the median, ˜x, butnot mean, ¯x?A. the skewedness of the dataB. outliers added to the dataC. scale changes to the dataD. All of the above affect the median but notthe mean.E. None of the above affect the median but notthe mean.x3| Freq. Percent Cum.--------+-----------------------------200 | 3 3.30 3.30210 | 1 1.10 4.40220 | 6 6.59 10.99230 | 6 6.59 17.58240 | 9 9.89 27.47250 | 10 10.99 38.46260 | 15 16.48 54.95270 | 17 18.68 73.63280 | 23 25.27 98.90290 | 1 1.10 100.00--------+-----------------------------Total | 91 100.003. Which is the correct list of the 5 Number Sum-mary, if any, for this data?A. 200,225,245,265,290B. 200,225,245,265,290C. 200,230,270,280,290D. 200,240,260,280,290E. 200,240,260,270,2904. What can you say about the data representedabove? The first is Height of a student, thesecond is Mom’s Height, and the third is Dad’sHeight.A. Mom’s Height is the most normal in shape.B. Mom’s are shorter than their children.C. Mom’s are shorter than their husbands(Dad’s).D. All of the above are true.E. Exactly two of the above are true.5. What is the IQR for Height(of a student), stillusing the boxplot above?A. 50%B. 1/2 of the rangeC. 10D. 7E. 176. Suppose you know that a distribution is bell-shaped with mean, ¯x = 25 and standard devi-ation, sx= 5, what would be the approximate85th percentile?A. 29.25B. 34.25C. 25.85D. 30E. 352STAT303 509–511 Exam #1, Form A Spring 20017. What can you say about the shape of the his-togram above? 4=Gray (I don’t know why it’smissing)A. It’s fairly normal since the peak is in thecenter.B. ‘Red’ is an outlier.C. The data is categorical, so the shape ismeaningless.D. The data is categorical, but the shape isnormal.E. Since the data is categorical, this graph isinvalid.8. Which of the following is the Fundamental Rulefor Using Data for Inference?A. Sample data can never be used to make in-ferences about a population. (You mustlook at the whole population.)B. Sample data can be used to make inferencesabout a much larger group if the data canbe considered to be representative with re-gard to the question(s) of interest.C. Any data can be used to make inferencesabout a much larger group if the data camefrom a random sample.D. Sample data can be used to make inferencesabout any larger group as long as the datacame from a random sample.E. Data is only useful if it came from a simplerandom sample.9. What can we say about z-scores?A. The mean of any set of z-scores is always 0whether the distribution is normal or not.B. We can determine the percentiles of any dis-tribution by looking at the z-scores.C. If we convert to z-scores, Q1and Q3alwaysfall within −1 and +1.D. All of the above are true statements.E. None of the above are true statements.10. Assuming the data above has a mean, ¯x = 20and standard deviation, s = 3, what can we sayabout the shape of the distribution?A. Since this is a normal quantile plot, we canuse the Empirical Rule and say about 95%of the observations will fall between 17 and23.B. Since this is a normal quantile plot, we canuse the Empirical Rule and say about 95%of the observations will fall between 14 and26.C. Since this is a normal quantile plot, we canuse the Empirical Rule and say about 95%of the observations will fall between 11 and29.D. The points don’t fit the line, so we can’t sayanything about the shape.E. The quantile plot shows the data is skewedto the right, so we can’t use the EmpiricalRule.3STAT303 509–511 Exam #1, Form A Spring 200111. If we know that a distribution is normal withmean, ¯x = 100 and standard deviation, sx= 10,what would mostly be the minimum value?A. 0B. 10C. 70D. 80E. 9012. Which of the 4 stages in statistics are most im-portant to you, a user of statistics?A. The Collection phase since that’s where weget the information.B. The Organization phase since that’s wherewe figure out what’s what.C. The Analyzation phase since that’s wherewe determine statistical significance.D. The Interpretation phase since that’s wherewe make our decisions.E. Each is important to anybody who readsthe newspaper.13. Numbering the boxplots above 1 to 5, which onemost likely has a mean greater than 200?A. No information about the mean can be de-termined from a boxplot.B. 5C. 4D. 3E. 214. What is the best definition of percentiles?A. A value in a dataset that occurs that per-cent of the time.B. A value in a dataset that has that percentof the observations less than or equal to it’svalue.C. A value in a dataset that has that percentof the observations equal to it’s value.D. A value in a dataset that has that percentas it’s value.E. None of the above are correct.| secAge| 509 510 511 | Total-----+---------------------------+--------19 | 1 2 3 | 620 | 11 2 13 | 2621 | 8 7 12 | 2722 | 8 8 6 | 2223 | 3 2 1 | 624 | 2 1 0 | 325 | 1 0 0 | 131 | 0 0 1 | 135 | 0 2 0 | 2-----+---------------------------+--------Total| 34 24 36 | 9415. According to the information above,A. the median age for section 510 is 22.B. the most likely (typical) student is 20 andin section 511.C. if you’re in section 509, you’re most likely20.D. All of the above are correct statements.E. None of the above are correct statements.16. How likely (what’s the probability) are you
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