Solve for R? sample data prob; I can find y-int, slope, but how to get R?

[HB09]

This is a SAMPLE problem from my class. I understand how to get slop and Y intercept BUT how do I get the R??

9.5	120
9.25	122
8	130
7.5	137
8	142
7	145
6	149
5.5	150	Slope -8.910278446
6.25	157	y intercept 205.8222757
5.75	158	r=-0.94

 

[ksdhart2]

This looks like an exercise from a stats class, so I'll guess that r has its typical meaning. You should have been given a formula for this. Perhaps something like this?

\(\displaystyle r=\displaystyle \frac{N \sum XY - \sum X \sum Y}{\sqrt{\left[N \sum X^2 - \left( \sum X \right)^2 \right] \left[N \sum Y^2 - \left( \sum Y \right)^2 \right ]}}\)

How far did you get in calculating and plugging in the requisite sums? Please share with us any and all work you've done on this problem, even the parts you know for sure are wrong. Thank you.

 

[stapel]

This is a SAMPLE problem from my class. I understand how to get slop and Y intercept BUT how do I get the R??

9.5	120
9.25	122
8	130
7.5	137
8	142
7	145
6	149
5.5	150	Slope -8.910278446
6.25	157	y intercept 205.8222757
5.75	158	r=-0.94

You ask about "R", but show "r". Are you asking how the exercise found the value of "r", or are you needing to find "R"? Since you appear to have only the two variables, I don't know that "R" is relevant...? (here)