According to the scatter chart, the sales trend type belongs to linear y=a+bt. If the time from July 2005 to June 2005 12 is 1, 2, 3, 4, 5, 6, then a= 137.27 and b=5.83 can be obtained according to the formula.
The method of forecasting the sales in the first month of 2006 is to substitute t=7 into the trend equation.
The predicted value is:137.27+5.83 * 7 =178.07.