The average price per gallon of gasoline in major U.S. cities for each month during a three-year period are shown in the following table:

(a) Using exponential smoothing with a = 0.45, what is the gasoline price forecast for January of year 4?
(b) What is the linear trend equation that best fits the data? Forecast the average gasoline price for January of year 4 by using this equation.
(c) Which method is more accurate?

Transcribed Image Text:

4 271 231 82 3 6 63 445 321 4 1 87 302 959 0) 1 918 558 5 46 55 5 54 3 3 6969 251 788 950 4 999 111 12 2 22 1 74 85 8 7 2 MJ JAS