You have estimated a linear regression model relating y to x. your professor says, "i think that the relationship between y and x is nonlinear." how would you test the adequacy of your linear regression? (check all that apply )
a. compare the fit between of linear regression to the non-linear regression model.
b. there is evidence in favor of a non-linear relationship if there is zero correlation between the dependent and independent variable.
c. if adding a quadratic term, you could test the hypothesis that the estimated coefficient of the quadratic term is significantly different from zero.
d. all of the above.

C

Step-by-step explanation:

If we add a quadratic term to our correlation and its coefficient is tending to zero, we can say that the term becomes unnecessary and therefore the relationship between the variables X and Y tends more to be linear. We can also check the correlation coefficients when making the two correlations.

1. 3

2. 4

3. 1

hope this ! have a great day.

-wfz

step-by-step explanation:

we are given a graph for system of inequalities.

in order to write the system of inequalities for the given graph, we need to find the inequality for each of the line separately.

let us find the slope of dotted line first.

taking two coordinates on the graph.

let us say (0,0) and (3,1).

let us find the slope of the line now.

slope of the dotted line would be =.

y-intercept of dotted line is y=0 only.

plugging slope m= and b=0 in slope-intercept form y=mx+b, we get

.

the line is shaded up of that dotted line.

therefore, for shading up we would take greater than inequality symbol > .

and because it's a dotted line we would take only > symbol in place of = sign in above equation of line.

therefore, inequality for dotted line would be

let us take two points (3,1) and (0,4) on the solid line.

slope of the solid line would be =.

for the solid line we have y-intercept b= 4.

plugging slope m= -1 and b=4 in slope-intercept form y=mx+b, we get

y = -1x + 4.

the line is shaded down of that solid line.

therefore, for shading down we would take less than inequality symbol < .

and because it's a solid line we would take ≤ symbol in place of = sign in above equation of line.

therefore, inequality for solid line would be