Finding value representing the indicated percentiles help!

Izzy

New Member
#1
Hi, I am having some issues solving this problem involving stock prices for indicated percentiles.



Use the following set of stock prices (in dollars)...

10 7 20 12 5 15 9 18 4 12 8 14

Find the stock price representing the indicated percentiles...

25th
&
95th


What I did for the problem was....

I picked 12 because I thought that was for the amount of data points in the set.

25= (k/12)100
25(12)/100 = 3 (round up) ---> $4

&

95 = (k/12)100 = 95(12)/100 = 11.4 --> $12

I thought this answer was correct, but looking at the back of the book for the 95th percentile I was way off. Please help!

I used the formula P=(k/n)100