Barbara lynch is the product manager for a line of skiwear produced by Health Co Industries and privately branded for sale under several different names .A part of Ms Lynch's is to provide a Quarterly forecast of sale for the northern United State ,a region composed of 27 states stretching from Maine to Washington. A 10 years history is shown.© BrainMass Inc. brainmass.com December 15, 2020, 2:47 pm ad1c9bdddf
Please see the attachments.
a) Time Series Plot
The time series plot of sales suggests that there is linear trend in the sales during 1994Q1 to 2003Q4. There is also some seasonal fluctuations. We can fit a trend equation and predict the value of sales.
b) Trend Equation.
The trend can be estimated by the least squares method. The general form of trend equation is Y =a+bx. Where a is known as the intercept, b is the slope. The value of slope gives the change in sales for a unit increase in the time.
The details are given below.
Trend Analysis for Sales
Fitted Trend ...
This solution gives the step by step method for analyzing time series data.