Question

A scatter plot contains a trend line with a slope of -1/10. Does this trend line illustrate a correlation?

Answer 1

A. Yes, there is a positive correlation.
B. Yes, there is a negative correlation.
C. No, there is no correlation.
D. There is not enough information.

Answer 2

is that all you're given? or are you given the correlation coefficient as well?

Answer 3

thats all thats given

Answer 4

ok well ideally you would have the correlation coefficient (or the data values to find the correlation coefficient) because this will help you determine how strong the linear correlation is

Answer 5

but because this critical piece of info is missing, it's hard to say how strong the correlation is

which leads me to think it's either B or D

if the correlation is strong enough, then you'll have a negative correlation

however, we don't have enough info (as I said above), which is why D could be an answer as well

Answer 6

see what I'm saying?

Answer 7

yea

Answer 8

If I were answering this, I guess I would lean more towards D since that missing piece of info is very critical

However, they could have easily implied that the correlation coefficient is assumed to be -0.5 or smaller, not sure though

Answer 9

A scatter plot contains the points (-3, 7) and (-1, 2). Does this scatter plot illustrate a correlation?

would this be a negative correlation?

Answer 10

it only contains those points? and nothing else?

Answer 11

yes

Answer 12

ok luckily all you have to do is find the slope of the line through those two points

Answer 13

using the slope formula

m = (y2 - y1)/(x2 - x1)

Answer 14

(-3^2 - 7^1) / (-1^2 - 2^1)=5.3^_ ?
@jim_thompson5910

Answer 15

i should have stated that the 2's and 1's aren't exponents

Answer 16

they're just ways to label the two sets of x and y values (so you can tell them apart)

Answer 17

oh ok

Answer 18

slope through (-3, 7) and (-1, 2)

m = (y2 - y1)/(x2 - x1)

m = (2 - 7)/(-1 - (-3))

m = (2 - 7)/(-1 + 3)

m = ???

Answer 19

-2.5

Answer 20

you got a negative slope (which is correct), so you have a negative correlation

it's actually a perfect negative correlation because there are only two points on this scatter plot