National Scan, Inc., sells ratio frequency inventory tags. Monthly sales for a 6-month period were as follows:
|
Month:
|
Sales
|
|
Feb
|
23
|
|
Mar
|
35
|
|
Apr
|
31
|
|
May
|
37
|
|
Jun
|
56
|
|
Jul
|
51
|
Disregard the demand pattern of the given time series, You are asked to use the time series to derive a trend equation. In order to derive the trend equation is Ft = a + bt, you have to compute several components to compute the values for the variables a and b. Answer the following questions pertaining to information that are relevant to deriving the trend equation.
a) The Sty =
b) The Sy =
c) The value for the b (slope of the trend line) = (in 3 decimal places)
d) The value for the a (intercept of the trend line) = (in 3 decimal places)