STATS Homework 4 Assignment

Question 1
Examine the time series provided in Excel #1a-c to identify the components present
(trend, cyclical, seasonal, and/or irregular), with an indication of whether the component
seems strong, moderate, or weak. Provide a brief explanation to support your
conclusions.
Type your answer here
Question 2
Explain and contrast the four measures of forecast accuracy.
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Question 3
The average SAT verbal score for students from one high school over the last ten exams
is 508, 490, 502, 505, 493, 506, 492, 490, 503, 501
Do the scores support an increasing or a decreasing trend? Explain.
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Question 4
The number of properties newly listed with a real estate agency in each quarter over the
last four years is given below. Assume the time series has seasonality without trend.
Year
Quarte
1
r

2

3

4

1

73 81 76 77

2

89 87 91 88

3

123 115

4

92 95 87 97

10
120
8

a.

Develop the estimated regression equation that minimize the sum of squared error
(highest R^2).

b.

Evaluate the accuracy of that estimated regression equation against known data.

c.

Forecast the four quarters of Year 5.

Question 5
A 24-hour coffee/donut shop makes donuts every eight hours. The manager must
forecast donut demand so that the bakers have the fresh ingredients they need. Tab #5
contains the actual number of glazed donuts (in dozens) sold in each of the preceding

13 eight-hour shifts. Forecast the demand for glazed donuts for the Day, Evening, and
Night shifts of June 8.
Type your answer here
Question 6
Quarterly revenues (in $1,000,000's) for a national restaurant chain for a five-year
period are shown in Tab #6 of the Excel file. Forecast the four quarters of year 6.
Type your answer here
Question 7
Business at Terry's Tie Shop can be viewed as falling into three distinct seasons: (1)
Christmas (November-December); (2) Father's Day (late May - mid-June); and (3) all
other times. Average weekly sales (in $'s) during each of these three seasons during
the past four years is shown in Tab #7 of the Excel file. Forecast sales for the next
year.
Type your answer here
Question 8
Coyote Cable has been experiencing an increase in cable service subscribers over the
last few years due to increased advertising and an influx of new residents to the
region. The number of subscribers (in 1000's) for the last 16 months are shown in Tab
#8 of the Excel file. Forecast subscription rates for months 17, 18, 19, 20.
Type your answer here
Question 9
Weekly sales of the Weber Dicamatic food processor for the past ten weeks are shown
in Tab #9 of the Excel file
a. Determine, on the basis of minimizing the mean square error, select the most
appropriate moving average model to use.
b. Forecast sales for week 11 using the model selected in a.
Type your answer here
Question 10
Connie Harris, in charge of office supplies at First Capital Mortgage Corp., would
like to predict the quantity of paper used in the office photocopying machines per
month. She believes that the number of loans originated in a month influence the
volume of photocopying performed. She has compiled the following recent monthly
data:
Number of Loans
Originated

Sheets of Photocopy Paper Used (000s)

25

16

25

13

35

18

40

25

40

21

45

22

50

24

60

25
a. Develop the regression equation that relates sheets of photocopy paper used to
loans originated.
b. Use the regression equation developed in part (a) to forecast the amount of paper
used in a month when 70 loan originations are expected.