Let the trip rate of a zone is explained by the household size done from the field survey. It was found that the household size are 1, 2, 3 and 4. The trip rates of the corresponding household is as shown in the table below. Fit a linear equation relating trip rate and household size. EXPLAIN THE SOLUTION THOROUGHLY and where did the 3 on sigma X came from?
Extracted text: Ex 3x1+3x2+3х3+3x4 — 30 Ex? 3x (1?) +3x (2?) +3 x (3?) +3 х (4?) %3D 90 ||
Extracted text: Household size (x) 1 2 3 4 Trips 1 2 4 per 2 4 5 7 day(y) 2 3 4 Ey 5 9 12 17