Question

Find the value of the 90th percentile of the following set of data.

18, 9, 7, 5, 11, 7, 17, 20, 19, 2, 17, 12, 5, 1, 13, 12, 11, 15, 16, 20

Answer 1

Arrange the things in increasing order.

20 values = 100%
90% = 18th value

Pick the 18th value for 90% percentile

Answer 2

the 18th value seems off to me ....

Answer 3

90 * 20/100 = 18 is not a decimal value so some interpolation is suggested

Answer 4

the average of the 18th and 19th positions is what im familiar with; but there are more exacting ways to approach it

Answer 5

a.20
b.19
c.11
d.9
these r the options

Answer 6

1; Order all the values in the data set from smallest to largest.
2; Multiply the total number of values by .9
3; If the value obtained in is not a whole number, round it up to the
nearest whole number; and pick the nth numebr from the set.

If the value obtained IS a whole number, count the values in your data
set from left to right until you reach the nth value, then average that value
the value that directly follows it.


since 20*.9 = 18 IS a whole number, you want to average the 18th and 19th positions

Answer 7

vvvvv
1, 2, 5, 5, 7, 7, 9, 11, 11, 12, 12, 13, 15, 16, 17, 17, 18, 19, 20, 20

which averages to 19.5

Answer 8

so 19 then?

Answer 9

19 or 20 ... id say prolly guess that the "correct" option they want you to choose is 19, but again, that is not the correct answer with regards to what the question is asking :/

Answer 10

ok

Answer 11

if it asked you to find the median; which corresponds to the 50th percentile

20*.5 = 10, but the median is the average of the 10th and 11th positions .... which in this case are the same value, but the principle is whats important. A whole number gets an average.