this is confusing?

[physics]

The correlation b/n 2 variables x and y is -0.75. which is true?
As x increases, y tends to increase

OR

An increase in x causes y to decrease

[Ilovemathsmeth]

Rule of thumb with such questions: correlation does NOT cause something to happen. Only indicates a relationship.

Thus you'd probably say as x increases, y TENDS to decrease. You'd lose marks if you said CAUSES.

[physics]

and another question
correlation of determination r^2 =0.49 so r= 0.7

or is it -0.7
A competent driver would score high in driver cotnrol ability. (i would assume theri saying that if we dont drink as much we will be better) so it would be -ve answer?

[stonecold]

Rule of thumb with such questions: correlation does NOT cause something to happen. Only indicates a relationship.

Thus you'd probably say as x increases, y TENDS to decrease. You'd lose marks if you said CAUSES.

learnt that at umat prep haha!

[Ilovemathsmeth]

I think it's coefficient of determination?

Yes, it can be positive or negative. So if you read the statement, I guess you'd say that as the level of competency decreases (affected by old age, alcohol), the level of performance in the test decreases. So as competency increases, performance increases. This question is a bit vague though. I'm guessing it's positive 0.7?

[stonecold]

and another question
correlation of determination r^2 =0.49 so r= 0.7

or is it -0.7
A competent driver would score high in driver cotnrol ability. (i would assume theri saying that if we dont drink as much we will be better) so it would be -ve answer?

wouldn't it be positive, because as competence increases, so does the score?

[physics]

oh i didnt know what the word competance meant thats why thanks !

[stonecold]

good that you're thinking like that though because vcaa are pretty much bound to give you a negative graph with a r² value, and tell you to give the r value.  the amount of people who forget to change it to a negative is laughable...

[physics]

aiyahhhh! i'm goanna  kaboom myself soon

The seasonal indices for the sales of takeaway food.
Season                 summer  autumn   winter   spring
Seasonal index          0.87    0.94        1.12     (dunno)

Would it be 0.93,    0.98, 1, 1.07,  1.1
please explain how u got the answer cause i guessed it to be 0.93
thank you very much