A company is modelling its revenue based on the sales make by its marketers, its summer sales, fall sales and winter sales for all the units in $000. It determined the following regression model from a sample of 35.

where

ŷ = Revenue
x₁ = Marketers’ sales
x₂ = Summer sales
x₃ = Fall sales
x₄ = Winter sales

The numbers below the coefficients are the coefficient standard errors.
a. Interpret the estimated coefficient on x₁.
b. Using the Durbin-Watson statistic, test at the 5% level the null hypothesis of positive autocorrelation of error terms.
c. Estimate the autocorrelation parameter.

Transcribed Image Text:

ŷ = d = 149 + 1.59x₁ + 3.74x2 + 1.26x3 + 2.91x4 (0.092) (0.745) (0.034) (0.056) 1.09