=+47. Oakland passengers, part 2. In Exercise 29, we created a linear model describing the trend in the number of passengers departing from Oakland (CA) airport each month since the start of 1997. Here’s the residual plot, but with lines added to show the order of the values in time: Residuals 8.0 10.0 12.0 14.0 16.0 Years since 1990 M16_SHAR8696_03_SE_C16.indd 577 14/07/14 7:38 AM 578 CHAPTER 16 Understanding Residuals