Download STAT303 Exam #1, Fall 2000 - Statistics - Prof. J. Carroll and more Exams Data Analysis & Statistical Methods in PDF only on Docsity!
STAT303 Secs 508–
Fall 2000
Exam
Form A
Instructor: Julie Hagen Carroll
October 25, 2000
- Don’t EVEN open this until you are told to do so.
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- 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.
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- This exam is worth 100 points, and will constitute 20% of your final grade.
- Good luck!
- Which of the following statements is/are true?
A. The value of the median will change if you add 10 to the maximum in a dataset. B. The IQR covers 50% of the range (spread) of the data. C. A z-score tells us how many standard devi- ations an observation is from its mean. D. All of the above are true statements. E. Exactly two of the above are true state- ments (excluding D.).
- Which of the following is NOT affected by out- liers?
A. the mean, ¯x B. the z-scores C. the correlation coefficient D. Exactly two of the above are not affected. E. All of the ARE affected by outliers.
- Suppose you know that a distribution is bell- shaped, with mean, x = 30 and standard de- viation, sx = 4. Approximately what percent of the data will fall between 22 and 34?
A. about 95% B. between 50 and 68% C. about 80% D. between 95 and 100% E. about 75%
- Numbering the boxplots 1 through 4 from left to right, which distribution is approximately uni- form?
A. You can’t tell by looking at a boxplot. B. 3 only since it’s the most spread out. C. 4 only since it’s the most symmetric. D. Both 3 and 4 are uniform. E. None of the boxplots are uniform.
- Which boxplot has an Interquartile Range, IQR, of about 20?
A. 1 B. 2 C. 3 D. 4 E. 1,2 and 4 are all the same.
- When can we correctly apply the Empirical Rule?
A. The Empirical Rule can be applied to any of the datasets. B. Only if the data is bell-shaped. C. Only if the data is symmetric. D. All of the above are true. E. Exactly two of the above are true.
- Which of the following are ’better’ statistics for the distribution above?
A. The median and the range since the data is skewed. B. The median and the IQR since the data is skewed. C. The mean and the standard deviation since the data is skewed. D. The mean and the IQR since the data is skewed. E. The median and standard deviation are al- ways the best statistics to use.
- Which of the following best describes the distri- bution above?
A. The mean is approximately 50 and the stan- dard deviation is about 10. B. The mean is approximately 50 and the stan- dard deviation is about 20. C. The median is approximately 50 and the interquartile range is about 10. D. Exactly two of the above are true. E. You cannot tell the mean and standard de- viation from a histogram.
| Gender Driver| F M | Total ------+-----------------+------- aggres| 37 31 | 68 passve| 14 16 | 30 timid| 1 1 | 2 ------+-----------------+------- Total| 52 48 | 100 Pearson chi2(2) = 0.5036 Pr = 0. (p-value)
- Are ‘type of Driver’(aggressive, passive or timid) and ‘Gender’ statistically related?
A. Yes, they are statistically related because the p-value is large. B. No, they are not statistically related be- cause the p-value is large. C. Yes, males are more aggressive than fe- males. D. No, only 1 male and 1 female are timid drivers. E. We would need the correlation coefficient to tell the strength of the relationship.
- Using the previous table, how likely are you to be an aggressive driver if you are female?
A. 37/ B. 37/ C. 68/ D. 52/ E. 37/
- How likely are you to be a passive male driver?
A. 16/ B. 16/ C. 30/ D. 16/ E. 48/
- Which of the following is NOT true?
A. Social Security Number is a discrete nu- meric variable. B. Classification is a an ordinal variable. C. Height is a continuous numeric variable. D. Number of cars that just ran the red light is a discrete numeric variable. E. All of the above are true.
- How would you describe the correlation of the data above?
A. Strongly negative B. Moderately negative C. Weak D. Moderately positive E. Strongly positive
1C,2E,3C,4B,5A,6B,7B,8D,9E,10E,11B, 12B,13C,14D,15A,16B,17A,18D,19A,20C
