Posted by Jen on .
For the table that follows, answer the following questions:
x y
1 1/2
2 1
3 3/2
4
 Would the correlation between x and y in the table above be positive or negative?
 Find the missing value of y in the table.
 How would the values of this table be interpreted in terms of linear regression?
 If a "line of best fit" is placed among these points plotted on a coordinate system, would the slope of this line be positive or negative?

Math 
MathMate,
Take
m1=(y(2)y(1))/(21)=0.5
m2=(y(3)y(2))/(32)=0.5
Since the slopes between any of the three points equal 0.5, so the first three points are collinear, and m1=m2>0 so the slope is positive.
Can you take it from here? 
Math 
Jen,
This is so confusing to me :( what would i do next??

Math 
MathMate,
If you wish, you can calculate the coefficient of correlation according to the method you use at school (mayer, median/median, etc.) using the first three pairs of data.
In the given case, the coefficient of correlation should be 1.0 because the first three points are collinear (fall on a straight line). The slope is positive (0.5), so the answer to the fourth question is positive.
I will let you calculate the coefficient of correlation (and confirm that it is 1.0).