Reference no: EM131200764

A student working on a summer internship in the economic research department of a large corporationstudied the relation between sales of a product (Y , in millions of dollars) and a population (x, in millionsof persons) in the firm's 50 marketing districts. The normal error regression model was employed. Thestudent first wished to test whether or not a linear association between Y and x existed. The studentaccessed a simple linear regression program and obtained the following information on the regressioncoefficients:95 PercentParameter Estimated Value Confidence Limits Intercept 7.43119 -1.18518 16.0476Slope 0.755048 0.452886 1.05721(a) The student concluded from these results that there is a linear association between Y and x. Isthe conclusion warranted? What is the implied level of significance?(b) Someone questioned the negative lower confidence limit for the intercept, pointing out that dollarsales cannot be negative even if the population in a district is zero. Discuss.