1. 4.1 Statistical Measures

2. When one needs to compare individual values to others in a data set, the following statistical measures are used: Per Capita Percent Change Percentile & Percentile Rank Weighted Mean

3. Per Capita Per capita represents the average amount per person Example 1. Calculate Canada’s per capita net worth if Canada’s net worth is $5, 702 billion and the population is 33 million Solution: 5 702 000 000 000 ÷ 33 000 000 = $172 787.88

4. Percent Change Measures a change in a value over time Percent change = (new value – old value) ÷ (old value) X 100% Example 2: A company’s profit in 2009 was $186000. In 2010 it was $325000. Calculate the percent change Percent change = (325000-186000) ÷186000 X 100 = 74.7%

5. Percentile A number (between 1 and 99) that represents the percent of the population with a score equal to or less than this number Example 3: The following were scores on a recent math quiz (out of 20): 5, 8, 9, 11, 11, 11, 13, 14, 16, 17, 18, 19

6. Percentile What percentile is a score of 13? Solution: 7/12 =0.583 = 59% (always round up) Therefore a score of 13 would be in the 59 th percentile. (59% would have a score of 13 or less)

7. Percentile Rank

9. Weighted Mean

11. Practice Page 205 #1, 2, 3, 4