Given the following quarterly sales data over a five-year period

Given the following quarterly sales data over a five-year period:

year 1 2 3 4 5
q1 20 37 75 92 176
q2 100 136 155 202 282
q3 175 245 326 384 445
q4 13 26 48 82 181

(a) What pattern or patterns are exhibited by these data?

 (b) Develop a multiple-regression model to predict sales using the Excel LINEST function.

 (c) Predict quarterly sales for year six using this equation.