Construct a 98% confidence interval for the average value of y for the given data; use x = 20, s_e = 108.0, and the equation of the regression line, = -44.85 + 15.24 x. Do not round the intermediate values. Round answers to 2 decimal places.

( ) E(y₂₀) ( )

A corporation owns several companies. The strategic planner for the corporation believes dollars spent on advertising can to some extent be a predictor of total sales dollars. As an aid in long-term planning, she gathers the following sales and advertising information from several of the companies for 2009 ($ millions). Advertising Sales (y) 140 12.5 3.7 55 21.1 338 60.0 994 37.6 540 6.1 89 16.0 126 41.2 379