When reading the computer output, the regression equation is typically buried among other statistics. The value of the slope is
the coefficient of the explanatory variable. The value of the intercept is coeff. of the constant. For the problem, the regression equation is: number of aircraft = 2939.93 + 233.517 * (years since 1990)
how do I find the predicted number and the actual number of aircrafts flying in 1922?
Number of aircrafts = 2939.93 + 233.517 * (years since 1990).
The predicted number of aircrafts flying in 1992 (1922 does not make sense for this equation because it returns a negative number of aircrafts) is found by pluging in the years since 1990 to 1992 = 1992 -1990 = 2 =>
number of aircrats = 2939.93 + 233.517 * (2) = 3406.96.
That is the predicted number.
The actual number is on the graph. You just go to the explanatory value 2 (years since 1990) on the horizontal axis, move straight upward until you reach the corresponding point on the graph, and read its vertical coordinate (go horizontally to the left until the vertical axis)
If you find the discriminant it will tell you the number and types of roots. The discriminant is the value b^2 -4ac. a = 1 b = 1 c = 1 1^2 - 4*1*1 1-4 = -3 Since this is a negative number there will be 2 complex roots.
