Can anyone take me through a problem about percentiles step by step? Please? (:

Question

doc.brown · Answer

I love percent problems 0.5 out of 1

doc.brown · Answer

How much is that out of 100?

timaashorty · Answer

lol 50%

timaashorty · Answer

Will you help me? c;

doc.brown · Answer

Show your work:$$\frac{0.5}{1}\times\frac{100}{100}=\frac{50}{100}$$

doc.brown · Answer

What is your concern?

timaashorty · Answer

I didn't had to work it out. it's obvous that 0.5 is 1/2 of 1. which means 50% ;P

timaashorty · Answer

Find the values of the 30th and 90th percentiles of the data.
129, 113, 200, 100, 105, 132, 100, 176, 146, 152

timaashorty · Answer

That^ Do I need to put them in order first or what?

doc.brown · Answer

Statistics?

timaashorty · Answer

yeah

timaashorty · Answer

Do you know it?

doc.brown · Answer

Ok yes, put them in order.
the 30th percentile is the top 70%

doc.brown · Answer

You have ten numbers, I counted, which means you want the third biggest to the biggest
then you want the 9th biggest and the biggest, for the top 10% (90% and higher)

timaashorty · Answer

$$100  $$
	$$100 $$ 
	$$105     $$
	$$113$$
$$	129   $$	$$132  $$ 
$$	146   $$	$$152  $$
$$	176 $$	$$200   $$

timaashorty · Answer

wait so 
3rd biggest is 105

and 9th biggest is 176

timaashorty · Answer

I have that as one of my answer choices. is that all we do ?

doc.brown · Answer

Yeah, let me put it this way:
If a number is in the 90th percentile, it is higher than 90% of the other scores

timaashorty · Answer

and if it's the 3oth percentile it's 30 % of the other numbers?

doc.brown · Answer

Higher than 30%

doc.brown · Answer

If you are in the 51st percentile, you are doing better than half your class.

timaashorty · Answer

Thank very much! You really helped [: