Question

For the data set

1
17 17 18 20
32 32 33 34 34 36 38 39 43 44
2 3 4 7 7 7 8 11 12 12 15 15 16 17
20 22 24 24 25 26 26 26 26 27 30
45 46 47 47 48
51 52 52 53 54 54 54 55 56 58 58 59 61 63 65
65 67 69 70 73 75 75 76 77 77 79 80 81 82 82


How do I find the 17th percentile of this list of numbers

Answer 1

15.58

Explanation:

1. Arrange n number of data points in ascending order: x1, x2, x3, ... xn

2. Calculate the rank r for the percentile p you want to find: r = (p/100) * (n - 1) + 1

3. If r is an integer then the data value at location r, xr, is the percentile p: p = xr

4. If r is not an integer, p is interpolated using ri, the integer part of r, and rf, the fractional part of r:

p = xri + rf * (xri+1 - xri)