QMB exam 1 practice

QMB exam 1 practice - Spring 2007 Exam 1 Chart applies to...

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Spring 2007 Exam 1 Chart applies to questions 4-8 10.97 11.00 12.56 12.63 13.37 13.99 14.22 14.52 14.60 14.76 15.23 15.66 15.87 16.33 16.79 16.82 16.82 16.84 17.21 17.98 18.52 18.54 19.25 20.40 20.81 20.99 22.01 22.65 22.82 22.90 24.46 26.26 27.11 27.21 27.46 29.23 36.87 38.90 38.92 47.50 55.30 4. The data above represent the rent paid per square foot of floor space for a small office in one of several large cities. Some computer analysis with PHStat on this data shows that the three quartiles are 15.23, 18.53 and 26.26. If you do the standard outlier check with this data, how many points would be considered either possible or definite outliers? A. 4 or more B. 3 C. 2 D. 1 E. 0 Answer: Given: Q1=15.23, Q2=18.53, Q3=26.26. Lower Fence =Q1-1.5(IQR)=15.23-1.5(26.26-15.23)= -1.315 . Upper Fence =Q3+1.5(IQR)=26.26+1.5(26.26-15.23)= 42.805. Only 2 fall outside fences, 47.50 and 55.30. 5. Nationally, any small office that goes for $18 or less per square foot is considered in the “low rent” category. Use the above to make a 95% confidence interval estimate for the proportion of all small offices in the “low rent” category. What is the upper endpoint of this interval? .62 .66 .70 .74 Choose one answer: <-------+-------+-------+-------+-------> A B C D E Answer(B): 6. In class we talked about the minimum size of the sample we would need to make sure we could adequately approximate probabilities in this situation using a normal distribution. The rule said that “a certain quantity” had to be at least 9. What does that “certain quantity” evaluate to in this case, where we are estimating the proportion in the low rent category? 10.15 10.35 10.55 10.75 Choose one answer: <-------+-------+-------+-------+-------> A B C D E Answer(B):From formula sheet, np(1-p)>9. So, 41(.488)(1-.488)=10.24>9 8. Suppose we are using the guidelines in our textbook for constructing a histogram for this data. Correctly or incorrectly, suppose we have decided to use 5 categories or classes for the histogram. If so, what would be a reasonable first category? A. 10 to 18-not good. Interval wont reach highest value (total width=40) B. 10 to 25-interval width is too 15-too wide C. 10 to 15-interval width is 5-too narrow D. 15 to 25-width is okay, but misses values from 10-15 E. 10 to 20-interval width is OK, contains all values (last interval is 50-60) Answer (E): interval width=(maximum-minimum)/# of intervals=(55.30-10.97)/5=8.866 Round that answer to 9 or 10. What to consider about good fit for bins : (1) width should be consistent with formula (2) first and last intervals contain data (3) interval widths all same In a doctor's office, it appears that the length of time a patient has to wait past the time of his/her scheduled appointment follows a normal distribution. A sample of 25 randomly selected patients had to wait an average of 16 minutes past the time of their scheduled appointment before being seen by the doctor, and these times had a standard deviation of 5
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This note was uploaded on 04/15/2008 for the course QMB 3250 taught by Professor Thompson during the Spring '08 term at University of Florida.

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QMB exam 1 practice - Spring 2007 Exam 1 Chart applies to...

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