Question

Percentile Question...easy, I'm sure, but I'm having trouble wrapping my head around this is figured...Thank you...

Score:     12   13     14     15     16     17      18    19   20

Percent: 6% 8%   18% 24% 18%   10% 8% 6%   2%

a) What score is the 25th percentile?

b) What score is the 75th percentile?

c) What score is the 70th percentile?

Answer 1

To get percentiles,

first to sort the Scores in ascending order of magnitude,

First 1 - 6 points = 12

7 - 14^th points = 13

15^th - 32^th points = 14

33^th - 56^th points = 15

57^th - 74^th points = 16

75^th - 84^th poinst = 17

85^th - 92^th points = 18

93^th - 98^th points = 19

99^th - 100^th points = 20

Number of data points = 100

a) To get the 25^th percentile, i.e 100* 0.25 = 25^th point in the sorted data

So, 25^th percentile = 14

b) To get the 75^th percentile, i.e 100* 0.75 = 75^th point in the sorted data

So, 25^th percentile = 17

c) To get the 70^th percentile, i.e 100* 0.70 = 70^th point in the sorted data

So, 25^th percentile = 16