Two variables are correlated with r=−0.31.

which answer best describes the strength and direction of the association between the variables?

weak positive
weak negative
strong negative
strong positive

weak negative

Step-by-step explanation:

we know that

The correlation coefficient r measures the direction and strength of a linear relationship. It can take a range of values from +1 to -1.

Values between -0.5 and -1.0 or 0.5 and 1.0 indicate a strong negative/positive linear relationship

Values between -0.3 to -0.1 or 0.1 to 0.3 indicate a weak negative/positive linear relationship

In this problem

The correlation coefficient for the data is −0.31

therefore

Is a weak negative correlation

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1