In time-series analysis, one approach to modeling trends in data involves the use of a trend-line regression. A common method to capture trends is the linear trend model, which can be represented by the equation:
$$ Y_t = eta_0 + eta_1 t + eta_2 t^2 + ext{error} $$
where:
After estimating the coefficients using ordinary least squares, the analysis reveals that $$ eta_0 = 5 $$, $$ eta_1 = 2 $$, and $$ eta_2 = 0.5 $$. What is the predicted value of $$ Y $$ for $$ t = 4 $$?