Question

The table shows exam scores of students who watched a certain number of hours of television per week.

Hours of TV 1 2 3 4 5 6 7 8 9 10
Exam Score 98 96 95 94 90 85 81 80 75 72

Calculate the correlation coefficient.
-0.99

-0.89

-0.79

-0.69

Answer 1

How do u find the correlation coefficient?

Answer 2

D:

Answer 3

Can any one help?

Answer 4

Do you have a graphing calculator? Or are you not allowed to use such devices?

Answer 5

Nope.

Answer 6

Oke, you have a 2 datasets: hours of TV and Exam Score. Let's call them x and y.
You need to calculate the mean of x and y

Then subtract the mean of x from every x value, you can call them a
Then do the same for y and call them b

Then you calculate a*b, a squared and b squared

So you should have 7 rows by now: x, y, a, b, a*b, a^2 and b^2

Then sum up everything for each row in a*b, a^2 and b^2

Put those values in the following formula:
sum(a*b) / sqrt(sum(a^2)*sum(b^2))

That would give you the correlation coefficient.

Answer 7

@undeadknight26 You still there?

Answer 8

I undeadstand...nothing you just said sorry...i was taking some time to figure it out...

Answer 9

we can do it step by step. Step one is to calculate the mean of x and y.
Do you know how to do that?

Answer 10

add all of x up and divide it?
add all of y up and divide it?

Answer 11

yes, divide them by the total number

Answer 12

ok.

Answer 13

did you get the mean of x and y?

Answer 14

hello?

Answer 15

I guess you don't want to learn how to do this? Cuz I'd be happy to explain it.

Answer 16

What was the answer? @undeadknight26

Answer 17

@undeadknight26

Answer 18

what was this?

Answer 19

because im doing this now