Five assessment-to-sale ratios are 0.90, 0.95, 1.00, 1.05 and 1.10. The median ratio is 1.00. What is the coefficient of dispersion?
Correct Answer
A) 6.0
Why this is correct: The coefficient of dispersion (COD) measures assessment uniformity. Calculate: 1) Find absolute deviations from median (1.00): |0.90-1.00|=0.10, |0.95-1.00|=0.05, |1.00-1.00|=0, |1.05-1.00|=0.05, |1.10-1.00|=0.10. Sum=0.30. 2) Average deviation = 0.30/5 = 0.06. 3) COD = (0.06/1.00) × 100 = 6.0. Why the other choices are wrong: "10.0" is wrong; it might come from misapplying the calculation. "20.0" is wrong; it might result from using the range or incorrect averaging. "30.0" is wrong; it might be the sum of deviations (0.30) misinterpreted. Exam tip: COD = (Average absolute deviation / Median) × 100. Lower COD means more uniform assessments.
Why This Is the Correct Answer
Why this is correct: The coefficient of dispersion (COD) measures assessment uniformity. Calculate: 1) Find absolute deviations from median (1.00): |0.90-1.00|=0.10, |0.95-1.00|=0.05, |1.00-1.00|=0, |1.05-1.00|=0.05, |1.10-1.00|=0.10. Sum=0.30. 2) Average deviation = 0.30/5 = 0.06. 3) COD = (0.06/1.00) × 100 = 6.0. Why the other choices are wrong: "10.0" is wrong; it might come from misapplying the calculation. "20.0" is wrong; it might result from using the range or incorrect averaging. "30.0" is wrong; it might be the sum of deviations (0.30) misinterpreted. Exam tip: COD = (Average absolute deviation / Median) × 100. Lower COD means more uniform assessments.
More appraisal-statistical-methods Questions
A price index rises from 100 to 121 over two years. What compound annual rate does this represent?
A sample of four sales drawn from a market with 200 annual transactions is:
A set of comparable sales has a mean of $250,000 and a standard deviation of $20,000. What is the coefficient of variation?
A property sold for $400,000 and resold three years later for $463,050 with no physical change. What compound annual rate does this indicate?
An appraiser includes both 'total room count' and 'bedroom count' as independent variables in a regression model estimating single-family home sale prices. The variance inflation factor (VIF) for 'bedroom count' is calculated as 12.3. What is the most appropriate appraisal action based on this result?
An appraiser runs a regression of sale price on GLA, age, and a binary variable for 'renovated' (1 = yes, 0 = no). The estimated coefficient for 'renovated' is $18,400 with a standard error of $6,200 and a t-statistic of 2.97. Assuming a two-tailed test at α = 0.05 and 42 degrees of freedom, what conclusion is supported regarding the market's recognition of renovations?
To validate the functional form of a regression model used for adjustments, an appraiser plots residuals against predicted values and observes a clear inverted-U pattern. What does this pattern indicate, and what is the most defensible corrective action?
A histogram of neighborhood sale prices shows two distinct peaks. What does this most likely mean?
What does it mean to validate a regression model?
An appraiser includes months elapsed since each sale as a variable in a price model. What is this intended to capture?
People Also Study
Valuation Principles & Procedures
25% of exam
Property Description & Analysis
20% of exam
Market Analysis & Highest/Best Use
15% of exam
Appraisal Math & Statistics
15% of exam
USPAP (Ethics & Standards)
15% of exam