Download Exam 2 Sample Questions - Statistical Methods | STAT 303 and more Exams Data Analysis & Statistical Methods in PDF only on Docsity!
STAT303: Secs 508-
Fall 2006
Exam
Form A
Instructor: Julie Hagen Carroll
- Don’t EVEN open this until you are told to do so.
- Be sure to mark your CORRECT section number and your test form on the scantron!
- Sign your name where indicated on your scantron. You may keep this exam.
- There are 20 multiple-choice questions on this exam, each worth 5 points. There is partial credit. Please mark your answers clearly on the scantron. Multiple marks will be counted wrong.
- You will have 60 minutes to finish this exam.
- This exam is worth 100 points, and will constitute 15% of your final grade.
- If you are caught cheating or helping someone to cheat on this exam, you both will receive a grade of zero on the exam. You must work alone AND NOT discuss this exam with anyone until AFTER the grades are posted.
- Good luck!
- A sample is to the population as
A. a statistic is to a parameter. B. x is to μ. C. r is to ρ. D. All of the above are correct. E. Only two of the above are correct.
- Here is a two-way table of the numbers of college stu- dents (U.S. citizens only) classified by racial/ethnic group and by whether they attend a public or a pri- vate college. The entries are in thousands of students.
Public Private Total Non-Hispanic White 7094 1982 9076 Non-Hispanic Black 831 290 1121 Hispanic 336 47 383 Asian 166 32 198 Native American 68 9 77 Total 8495 2360 10855
How likely is a public college student to be non-Hispanic black?
A. 831/ B. 831/ C. 831/ D. 1121/ E. 8495/
- Using the same table, how likely is a student to be native American and attend a private college?
A. 9/ B. 9/ C. 9/ D. 77/ E. 2360/
- B ¯
LANK A in a sampling method means that the sample results will systematically misrepresent the population in the same way when we take repeated samples. For example, if we contact only people listed in telephone directories, the sample suffers from BLANK B. If some people chosen for the sample refuse to participate, the sample suffers from BLANK C. Both BLANK B and BLANK C are common sources of BLANK A. B ¯
LANK
A should read
A. bias B. random sampling error C. high variability D. undercoverage E. nonresponse
- If all of the boxplots have 100 observations, which one most likely has the largest standard deviation?
A. the first one since it has the worst (farthest away from the median) outliers B. the second one C. the third one since it has the most outliers D. the fourth one E. the sixth one
- Which boxplot would have the tallest bins (bars) if we made histograms of each? Again, there are 100 obser- vations in each dataset.
A. the first one B. the second one C. the fourth one D. the fifth one E. the sixth one
- Which of the statements does not contain a statistical blunder?
A. There is a strong negative correlation between a person’s gender and the amount that he or she pays for automobile insurance. Males must pay more for their insurance. B. The standard deviation of scores on the first STAT303 exam was s = −14 points. C. The mean height of young women is 64 inches, and the correlation between their heights and weights is 0.6 inches. D. The correlation between height and weight for adult females is about r = 1.2. E. All four statements contain blunders.
- If we wanted to show the relationship between drinking (yes or no) and income, which of the following should we use?
A. a two-way table with drinking as the column vari- able and income as the row variable B. side-by-side boxplots of income for drinkers and non C. a scatterplot of income vs. drinks per week D. two pie charts since drinking is a categorical vari- able E. Any of the above would work.
- Which best describes the correlation between MDadColl,x, and MMomColl, y?
A. strongly negative B. moderately negative C. weak D. moderately positive E. strongly positive
- Years of college for males’ moms, MMomColl, is on the y-axis, and years of college for males’ dads, MDadColl, is on the x-axis. If we switched the axes, let x be y and vice versa, which of the following would be true?
A. The new slope would be 1 over the old slope (the inverse). B. The new slope would be the old intercept and the new intercept would be the old slope (they would switch position since x and y switched). C. The correlation would be exactly the same. D. The new correlation would be 1 over the old cor- relation. E. Two of the above are true.
- Looking at the original plot (not the switched one), if we add a mom with 3 years of college and pair it with a dad with 5 years of college. What would this do to the correlation, slope and intercept?
A. Since the point (5,3) would be off of the line, the correlation would decrease, and the slope and in- tercept would change some. B. Since the point (5,3) is about the mean, none of the 3 statistics would change much. C. Since the point (3,5) would be off of the line, the correlation would decrease, but the slope and in- tercept would not change. D. Since the point (3,5) would be on of the line, the correlation would decrease, the slope decrease some and intercept would increase some. E. Since the point (3,5) would be off of the line, the correlation would decrease, the slope decrease some and intercept would increase some.
- Thirty magazines were ranked by educational level of their readers. Three magazines were randomly selected from the first ten, three from the second ten, and three from the third ten magazines. Six advertisements were randomly selected from each of the nine selected mag- azines. Which type of sampling method was used?
A. Simple random sampling B. Systematic samping C. Stratified random sampling D. Multistage sampling E. None of the above; this is not a good sampling technique.
1D,2C,3A,4A,5E,6A,7E,8B,9D,10B,11E 12E,13C,14D,15D,16B,17D,18C,19B,20D
