Our family owned a sari-sari store, then my dad noticed that the sales of our Coca-cola product was erratic from Monday to Sunday. He said that the sales from day 1 has a total of 15 then it became 16 then 7, 13, 11, 15, 10 in the following day.

Hey son, can help you me to find the value of the 40th percentile of our Coca-cola product?

Sure dad, I can help you on that thing!

So dad, the first thing we need to do is to arrange all the values in ascending order. Then, we will use the formula Pk = k/100 (n+1)

Okay son, that's great!

Then, substitute the given numbers to the formula, which n = 7 and k = 40

P40 = 40/100 (7+1)

P40= (8) 40/100

P40= 320/100

P40 = 3.2

P40 = 40/100 (7+1)

P40= (8) 40/100

P40= 320/100

P40 = 3.2

But dad, this is not the exact position of the value that we are finding.

Hmmm... do you have any idea?

Hmmm... I think we need to round off the value that we got earlier??

P40 = 40/100 (7+1)

P40= (8) 40/100

P40= 320/100

P40 = 3.2

Great job dad your'e right! So the estimated value will become 3, then the 3rd position in the given data is 11

7,10, 11, 13, 15, 15, 16

So dad, the value of the 40th percentile that we were looking earlier is only 11!

And also, the meaning of the value 3.2 is the position of 40%!

Thank you son you helped me a lot!!

Therefore, the arrangement of the values will become 7, 10, 11, 13, 15,15 ,16

Okay okay I think get it.