Hi k9queen!
These are the answers to your questions:
Without doing any of the steps how do you know that the yearly trend
will be equal to zero? Explain
In order to compute the yearly trend, we would first need to know the
yearly sales. The given data is quarterly, so we just need to sum the
sales of all quarters in a year in order to get the sales amount that
year. Therefore, we have that:
Sales year 1999: 3820
Sales year 2000: 3820
Sales year 2001: 3820
Sales year 2002: 3820
Now, the slope of a trend line shows how sales are increasing or
decreasing over a number of years. However, in this case we have that
the sales are neither increasing nor decreasing! In fact, if we
graphed the sales against time we would get
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99 00 01 02 t
A trend line is the line that best fits those points. Clearly, the
best fit for the data is simply a horizontal line at 3820. Therefore,
the trend forecast for next year would be that the sales are 3820. The
yearly trend is equal to zero in that there is neither an increasing
nor a decreasing trend.
If the moving average for Q3 of 1999 is equal to 955, you know that
the moving average for any quarter is equal to what? How do you know
this?
The moving average for any quarter will also be 955. This is so
because, since sales each quarter are always the same, the moving
average (taken over the last 4 quarters) always takes the same values
when calculating the average. For example, the moving average for Q4
of 1999 would be the average among Q1 to Q4 of year 1999. That is, the
average of 900, 850, 970 and 1100 (which is 955). The moving average
for Q1 of 2000 would be the average among Q2-Q4/1999 and Q1/2000.
Since sales of each quarter are equal independently of the year, we
are calculating the average among the same numbers: 850, 970, 1100,
900. Thus we get 955 again. Clearly, this happens for every quarter of
every year.
I hope this helps! If you have any doubt regarding my answer, please
don't hesitate to request a clarification before rating it. Otherwise
I await your rating and final commetns.
Best wishes!
elmarto |
