=+29. Oakland passengers. Much attention has been paid to the challenges faced by the airline industry. Patterns in customer demand are an important variable to watch. The scatterplot below, created in Excel, shows the number of passengers departing from Oakland (CA) airport month by month since the start of 1997. Time is shown as years since 1990, with fractional years used to represent each month.

(Thus, June of 1997 is 7.5—halfway through the 7th year after 1990.) www.oaklandairport.com 600000 Passengers 7 9 11 13 Years since 1990 15 17 800000 1000000 1200000 1400000 Here’s a regression and the residuals, created in Excel 2013, plotted against Years since 1990:

SUMMARY OUTPUT Dependent Variable is: Passengers Regression Statistics R Square 0.711 Standard Error 104330 Coefficients Intercept 282584 Years since 1990 59704.4 17

-400000

-200000 0

Residuals 7 9 11 13 15 Years since 1990 200000

a) Interpret the slope and intercept of the regression model.