Quarterly Sales Revenue (In $Million) for a Particular Company Has

Essay

Quarterly sales revenue (in $million) for a particular company has been modelled using linear regression with indicator variables:
Y = 132 + 2Q₁ + 3Q₂ - 5Q₄ + 2t
Where t is time in quarters, with origin March 2006 and Q₁, Q₂ and Q₄ are the indicator variables for March, June and December quarters, respectively.
Describe the trend and seasonal effects.