AA7004P - MGT 780 - (EXERCISE 4) Forecasting QUESTION (5-33) A Major Source of Revenue in Texas Is A State Sales Tax On Certain Types of Goods and
AA7004P - MGT 780 - (EXERCISE 4) Forecasting QUESTION (5-33) A Major Source of Revenue in Texas Is A State Sales Tax On Certain Types of Goods and
QUESTION [5-33] A major source of revenue in Texas is a state sales tax on certain types of goods and
services. Data are compiled and the state comptroller uses them to project future revenues for the state
budget. One particular category of goods is classified as Retail Trade. Four years of quarterly data (in
$millions) for one particular area of southeast Texas follow:
Before forecasting the sales, a regression analysis has been run in order to generate an equation to
forecast the future sales. The analysis is as below:
Standard
Coefficients Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0%
Intercept 281.5625 5.753032 48.94159 3.18E-14 268.9002 294.2248 268.9002 294.2248
TIME 3.69375 0.428806 8.614042 3.21E-06 2.749955 4.637545 2.749955 4.637545
Q1 -75.6688 5.574474 -13.5742 3.25E-08 -87.9381 -63.3994 -87.9381 -63.3994
Q2 -48.8625 5.491392 -8.89802 2.34E-06 -60.949 -36.776 -60.949 -36.776
Regression Statistics
0.98424
Multiple R 4
0.96873
R Square 6
Adjusted R 0.95736
Square 8
7.67070
Standard Error 9
Observations 16
ANOVA
Significanc
df SS MS F eF
85.2110
Regression 4 20055.2 5013.8 7 3.34E-08
647.237 58.8397
Residual 11 5 7
20702.4
Total 15 4
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
The model shows the R Square value is 96%. The model can explain 96% of the sales. This indicates that
the variation of the Texas State revenue is proportionally explained by the independent variable of the
regression model which are the time, quarter 1, quarter 2 and quarter 3 values.
The Significance F analysis on the sales model also shows that it has a value of 3.34 x 10 -08. As this value
is less than 0.05, this means that the sales model generated is a significant model.
By looking at the Sales Forecast graph above, it shows that the sales were in an uptrend seasonal.
Through a judgmental prediction, it shows that the sales will be declining after period 16. Which means,
the sales will decline on the first quarter of the 5 th year and start incline on second quarter onwards. The
graph also shows that the forecast trending is close to the actual trend despite the slight difference
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
during period 8 where the forecasted sales were slightly higher than the actual sales and period 16
where the actual sales were slightly higher than the forecasted sales. Nevertheless, the forecast of this
model is correctly forecasting the actual value of the sales. Thus, the prediction for the future revenue of
the Texas state can be based on the forecasted value.
Tracking Model
Tracking
6.00
4.00
2.00
0.00
0 2 4 6 8 10 12 14 16 18
-2.00
-4.00
-6.00
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
By referring to the Tracking Graph above, the upper limit was set at tracking value of +$4 million while
the lower limit was set at -$4million. This is because ± 4 million is less than 5% from the total overall
budget. Thus, if the forecast is within this limit, it still workable for the state of Texas as it does not run
out from their expectation more than 5%. Throughout 16 period, the revenue of the Texas is within this
control boundaries. However, on the period 14, the revenue was slightly off the lower limit. This shows
that on the 2nd quarter of the 4th year, the Texas state might have faced a short decline in their economy
that caused its revenue to decline.
QUARTE FORECAS
YEAR R TIME Q1 Q2 Q3 T
5 1 17 1 0 0 268.69
5 2 18 0 1 0 299.19
5 3 19 0 0 1 299.69
5 4 20 0 0 0 355.44
Since the state of Texas already have this data, they should diversify their portfolio of income so that
their income would not follow any quarterly trend that based on weather condition, thus helping them
to generate constant income throughout the year.
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
QUESTION [5-35] Trevor Harty, an avid mountain biker, always wanted to start a business selling top-of-
the-line mountain bikes and other outdoor supplies. A little over 6 years ago, he and a silent partner
opened a store called Hale and Harty Trail Bikes and Supplies. Growth was rapid in the first 2 years, but
since that time, growth in sales has slowed a bit, as expected. The quarterly sales (in $1,000s) for the
past 4 years are shown in the table below:
Year 1 Year 2 Year 3 Year 4
Quarter 1 274 282 282 296
Quarter 2 172 178 182 210
Quarter 3 130 136 134 158
Quarter 4 162 168 170 182
Before forecasting the sales, a regression analysis has been run in order to generate an equation to
forecast the future sales. The analysis is as below:
Standard
Coefficients Error t Stat P-value Lower 95% Upper 95% Lower 95.0% Upper 95.0%
Intercept 150 4.76063403 31.50840814 3.90893E-12 139.5219151 160.4780849 139.5219151 150
TIME 2.05 0.35483671 5.777305282 0.00012332 1.269009667 2.830990333 1.269009667 2.05
Q1 119.15 4.612877233 25.82986583 3.38566E-11 108.9971257 129.3028743 108.9971257 119.15
Q2 19.1 4.544127079 4.203227522 0.001477526 9.098443734 29.10155627 9.098443734 19.1
-
Q3 -28.95 4.502373112 6.429942451 4.8749E-05 -38.8596564 -19.0403436 -38.8596564 -28.95
Regression Statistics
Multiple R 0.995391776
R Square 0.990804788
Adjusted R Square 0.987461075
Standard Error 6.347512039
Observations 16
ANOVA
Significance
df SS MS F F
296.318704 4.06547E-
Regression 4 47755.8 11938.95 9 11
40.2909090
Residual 11 443.2 9
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
Total 15 48199
The model shows the R Square value is 99%. The model can explain 99% of the sales a value that very
close to 100%. This indicates that the variation of the Hale & Harty Trail Bikes and Supplies is
proportionally explained by the independent variable of the regression model which are the time,
quarter 1, quarter 2 and quarter 3 values. The Significance F analysis on the sales model shows a value of
4.07 x 10-11. As this value is less than 0.05, this means that the sales model generated is a significant
model.
Variables
Year Quarter Sales Time Q1 Q2 Q3 Forecast FE MAD MSE MAPE
1 1 274 1 1 0 0 271.2 2.8 2.8 7.84 1.021898
1 2 172 2 0 1 0 173.2 -1.2 1.2 1.44 0.697674
1 3 130 3 0 0 1 127.2 2.8 2.8 7.84 2.153846
1 4 162 4 0 0 0 158.2 3.8 3.8 14.44 2.345679
2 1 282 5 1 0 0 279.4 2.6 2.6 6.76 0.921986
2 2 178 6 0 1 0 181.4 -3.4 3.4 11.56 1.910112
2 3 136 7 0 0 1 135.4 0.6 0.6 0.36 0.441176
2 4 168 8 0 0 0 166.4 1.6 1.6 2.56 0.952381
3 1 282 9 1 0 0 287.6 -5.6 5.6 31.36 1.985816
3 2 182 10 0 1 0 189.6 -7.6 7.6 57.76 4.175824
3 3 134 11 0 0 1 143.6 -9.6 9.6 92.16 7.164179
3 4 170 12 0 0 0 174.6 -4.6 4.6 21.16 2.705882
4 1 296 13 1 0 0 295.8 0.2 0.2 0.04 0.067568
4 2 210 14 0 1 0 197.8 12.2 12.2 148.84 5.809524
4 3 158 15 0 0 1 151.8 6.2 6.2 38.44 3.924051
4 4 182 16 0 0 0 182.8 -0.8 0.8 0.64 0.43956
Total -7.1E-14 4.1 27.7 2.294822
By looking at the graph, it shows that the sales are in a consistent trend seasonal. Through a judgmental
prediction, it is shows that the sales will be inclining after period 15 which is the first and second quarter
of the 5th year and then decline during the third and fourth quarter of the fifth year. The decline can be
explained by people doing less outdoor activities such as biking during the cold weather (winter)
assuming that quarter 1 start on 1 st of January of every year. The graph also shows that the forecast
trending is close to the actual trend. However, there is a slight difference on period 11 where the actual
sales declined slightly more than predicted. Nevertheless, the forecast of this model is still correctly
forecasting the actual value of the sales. Thus, the prediction for the future sales of the Hale & Harty Trail
Bikes & Supplies can be based on the forecasted value.
Tracking Model
Tracking Graph
6.00
4.00
2.00
0.00
0 2 4 6 8 10 12 14 16 18
-2.00
-4.00
-6.00
By referring to the Graph, the upper limit was set at tracking value of +$4 thousand while the lower limit
was set at -$4 thousand. Throughout 16 period, the revenue of the Hale & Harty Trail Bikes & Supplies is
within this control boundaries. This is because ± 4 thousand are less than 5% from the total overall
budget. Thus if the forecast is within this limit, it still workable for the Hale & Harty Trail Bikes & Supplies
as it does not run out from their expectation more than 5%. However, on the period 12 & 13, the
revenue was slightly off the lower limit. This shows that on the 2 nd quarter of the 3rd year that Hale &
Harty Trail Bikes & Supplies might facing a short decline in their overall financial that caused by their
revenue/sale are declining during that particular period.
In my opinion, Hale & Harty Trail Bikes & Supplies should use this information collected to analyse a
different strategy such as diversifying their products or other marketing/promotion strategy in order to
cover up for the sales loss during winter season. This is enable them to at least boost the sales towards
an upward trend instead of remaining a consistent seasonal trend.
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
QUESTION [5-39] The following table provides the Dow Jones Industrial Average (DJIA) opening index
value on the first working day of 1994-2013: Develop a trend line and use it to predict the opening DJIA
index value for years 2014, 2015, and 2016. Find the MSE for this model.
Naïve Model
By comparing of all model, Naïve model shows the best model to forecast the DJIA or normally been
refer to stock market index. This is based on comparing the MAD, MSE and MAPE value. Below shows
the graph comparing the forecast value of all model.
12000
10000
8000
6000
4000
2000
0
1990 1995 2000 2005 2010 2015 2020
DJIA Naive 2Y MA 2Y WMA ES
By doing simple comparison between DJIA with the forecast value for each model, Naïve model still
remain as the best model to forecast DJIA.
12000
10000
8000
6000
4000
2000
0
1994 1996 1998 2000 2002 2004 2006 2008 2010 2012 2014
DJIA 3754 Naive
10
6 Naive
Axis Title Linear (Naive)
4
0
f(x) =2000 2005 2010 2015 2020
1990 1995
R² = 0
Axis Title
Therefore,
Tracking Model
Cumulative
Period Year DJIA Naive FE RSFE lFEl lFEl MAD Tracking
1 1995 3834 3754 80 80 80 80 80.00 1.00
2 1996 5117 3834 1283 1363 1283 1363 681.50 2.00
3 1997 6448 5117 1331 2694 1331 2694 898.00 3.00
4 1998 7908 6448 1460 4154 1460 4154 1038.50 4.00
5 1999 9213 7908 1305 5459 1305 5459 1091.80 5.00
6 2000 11502 9213 2289 7748 2289 7748 1291.33 6.00
7 2001 10791 11502 -711 7037 711 8459 1208.43 5.82
8 2002 10022 10791 -769 6268 769 9228 1153.50 5.43
9 2003 8342 10022 -1680 4588 1680 10908 1212.00 3.79
10 2004 10453 8342 2111 6699 2111 13019 1301.90 5.15
11 2005 10784 10453 331 7030 331 13350 1213.64 5.79
12 2006 10718 10784 -66 6964 66 13416 1118.00 6.23
13 2007 12460 10718 1742 8706 1742 15158 1166.00 7.47
14 2008 13262 12460 802 9508 802 15960 1140.00 8.34
15 2009 8772 13262 -4490 5018 4490 20450 1363.33 3.68
16 2010 10431 8772 1659 6677 1659 22109 1381.81 4.83
17 2011 11577 10431 1146 7823 1146 23255 1367.94 5.72
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
Tracking Graph
9.00
8.00
7.00
6.00
5.00
4.00
3.00
2.00
1.00
0.00
0 5 10 15 20 25
Based on the tracking graph, it shows that this model have ± 8 in the result of their forecasting. Due to
rapid changes of the stock market, the forecast tracking should be at least around ± 1 as the investor are
risking their capital and off forecast result will make things worse and also make the forecast unreliable
to the investor. Forecasting data should be a helping tools to an investor or even industries to evaluate
the stock market situation.
To forecast more accurately, having an expectation of how the stock market might perform is important
in giving you a base for making your investment decisions. Using different analysis techniques and
comparing the results will improve the accuracy of the forecasting.
Based on the calculation, the forecast for 2014, 2015 and 2016 is as below:
Question 3-42: The following table gives the average monthly exchange rate between the U.S.
dollar and the euro for 2009. It shows that 1 euro was equivalent to 1.289 U.S. dollars in January
2009. Develop a trend line that could be used to predict the exchange rate for 2010. Use this
model to predict the exchange rate for January 2010 and February 2010.
Naïve Model
Tim
e Month EX.Rate Forecast FE MAD MSE MAPE
1 January '09 1.289
2 February '09 1.324 1.289 0.035 0.0350 0.0012 2.64
3 March '09 1.321 1.324 -0.003 0.0030 0.0000 0.23
4 April '09 1.317 1.321 -0.004 0.0040 0.0000 0.30
5 May '09 1.28 1.317 -0.037 0.0370 0.0014 2.89
6 June '09 1.254 1.28 -0.026 0.0260 0.0007 2.07
7 July '09 1.23 1.254 -0.024 0.0240 0.0006 1.95
8 August '09 1.24 1.23 0.01 0.0100 0.0001 0.81
9 September '09 1.287 1.24 0.047 0.0470 0.0022 3.65
10 October '09 1.298 1.287 0.011 0.0110 0.0001 0.85
11 November '09 1.283 1.298 -0.015 0.0150 0.0002 1.17
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
By comparing of all model, Naïve model shows the best model to forecast the future exchange rate. This
is based on comparing the MAD, MSE and MAPE value. Below shows the graph comparing the forecast
value of all model.
Forecast
12
10
6 Forecast
Axis Title Linear (Forecast)
4
0
0 f(x)
2 =4 6 8 10 12 14 16
R² = 0
Axis Title
Therefore,
Tracking Model
Time Month EX.Rate Forecast FE RSFE lFEl Cumulative lFEl MAD Tracking
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
Tracking
12.00
10.00
8.00
6.00
4.00
2.00
0.00
0 2 4 6 8 10 12 14 16
There are numerous methods of forecasting exchange rates, likely because none of them have been
shown to be superior to any other. This speaks to the difficulty of generating a quality forecast. Based on
this model, is shows that the model have ± 3 in the result of their forecasting. Throughout 12 period, the
average monthly exchange rate between the U.S. dollar and the euro was within this normal range.
However, on July 2009, the average monthly exchange rate went off the lower limit. Due to hostile and
rapid changes of the world currency, the forecast tracking should be at least around ± 1. This is because
even a slightly off forecasting can turn around the entire business plan for one company or even a
AA7004P - MGT 780 – (EXERCISE 4) Forecasting
nation. Therefore, in order to get a better forecasting, it is crucial to reduce the uncertainty and gather as
much information because the more data we have the less likely we will be caught in uncertainties. This
will help us to generate the best way to forecasting and get an accurate and reliable forecasting result to
the actual amount.
Thus, based on the calculation the forecast for Jan’ 10 and Feb’ 10 is as below: