Question

A regional planner is studying the demographics in a region of a particular state. She has gathered the following data on nine counties.

Country	Median Income		Median Age		Coastal
A	$47,963		56.4		1
B	49,585		58.9		1
C	46,440		57.5		1
D	46,391		41.2		1
E	34,806		39.4		0
F	39,416		41.2		1
G	35,549		41.3		0
H	30,796		33.5		0
J	32,233		21.7		1

(a)	Is there a linear relationship between the median income and median age? (Round your answer to 3 decimal places.)

(Click to select)NoYes, the correlation of Income and Median Age is .

(b)	Which variable is the "dependent" variable?
	Median Income Median Age

(c-1)

Use statistical software to determine the regression equation. (Round your answers to 2 decimal places.)

Income =  +  Median Age.

(c-2)

Interpret the value of the slope in a simple regression equation. (Round your answer to the nearest whole number.)

For each year increase in age, the income increases $  on average.

(d)	Include the aspect that the county is "coastal" or not in a multiple linear regression analysis using a "dummy" variable. Does it appear to be a significant influence on incomes? (Negative amounts should be indicated by a minus sign. Round your answers to 2 decimal places.)

Income =  +  Median Age +  Coastal

(e)	Test each of the individual coefficients to see if they are significant. (Round your answers to 2 decimal places. Negative amounts should be indicated by a minus sign. Leave no cells blank - be certain to enter "0" wherever required.)

Predictor	T	P
Median Age
Coastal

Answer 1

a) We need to use a scatter plot and chart Y: Median Income and X: Median Age

From the scatter plot we can see that there is a liner relationship between variables. We can find correlation coefficient to confirm it.

First find

Σx     =	363179
Σy     =	391.1
Σxy   =	16401870.3
Σx^2 =	15084090073
Σy^2 =	18202.49

Submit the values in the formula

r = 0.861

Which shows that variables have strong positive correlation

b) Dependent Variable is Y: Median Income

c) The regression summary is

Regression Equation is

For each year/unit increase in median age, median income increases by $18,042

d) The regression summary when dummy variable coastal is included

Income decreases by $552 for each unit increase in X when a dummy variable is included.

Only four sub questions per question