Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

t25 An economist is studying the job market in Denver area neighborhoods. Let x

ID: 3291608 • Letter: T

Question

t25

An economist is studying the job market in Denver area neighborhoods. Let x represent the total number of jobs in a given neighborhood, and let y represent the number of entry-level jobs in the same neighborhood. A sample of six Denver neighborhoods gave the following information (units in hundreds of jobs).

Complete parts (a) through (e), given x = 198, y = 29, x2 = 7402, y2 = 169, xy = 1094, and r 0.866.

(e) Find the value of the coefficient of determination r2. What percentage of the variation in y can be explained by the corresponding variation in x and the least-squares line? What percentage is unexplained? (Round your answer for r2 to three decimal places. Round your answers for the percentages to one decimal place.)


(f) For a neighborhood with x = 31 hundred jobs, how many are predicted to be entry level jobs? (Round your answer to two decimal places.)
hundred jobs

x 17 30 48 28 50 25 y 3 3 6 5 9 3

Explanation / Answer

e) Coefficient of determination = 0.866*0.866 = 0.750

% Explained = 75.0%

%unexplained = 25%

b) Equation will be

y = -0.37519+0.157834

for x = 31

y = -0.375+0.157834*31

y = 4.52 (Rounded to two decimal places)