A study was carried out to relate sales revenue y (in thousands of dollars) to a
ID: 3155900 • Letter: A
Question
A study was carried out to relate sales revenue y (in thousands of dollars) to advertising expenditure x (also in thousands of dollars) fast-food outlets duFind theg a 3 monthe period. A sample of 15 outlets yielded the accompanying summary quantities. sigmma x = 14.10 sigmma y= 1438.50 sigmma x^2 = 13.94 sigmma y^2 = 140,351 sigmma xy = 1385.20 sigmma (y - y-)^2 = 2401.87 sigmma (y - y^)^2= 561.47 What proportion of observed variation in sales revenue can be attributed to the linear relationship between revenue and advertising expenditure? (Give the answer to three decimal places.) Calculate s_e and s_b. (Give the answers to four decimal places.) s_e = s_b = Obtain a 90% confidence interval for b, the average change in revenue associated with a $1000 (that is, 1 unit) increase in advertising expenditure. (Give the answers to three decimal places.) You may need to use the appropriate table in Appendix A to answer this question.Explanation / Answer
c) Slope, b1=[Summation x*y-(summation x)*(summation y)/n]/{summation x^2-(summation x)^2/n}
=(1385.20-14.1*1438.50/15)/(13.94-14.10^2/15)
=48.11
90% C.I=slope+-tcrtical at df=n-2*SE(b1)
=48.11+-1.771*7.93468
=34.058 to 62.162
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.