GBA334 homework

23.Enrollment in a particular class for the last four
semesters has been 115, 120, 110, and 130. Suppose a
one-semester moving average was used to forecast enrollment
(this is sometimes referred to as a naïve
forecast). Thus, the forecast for the second semester would
be 115, for the third semester it would be 120,
and for the last semester it would be 110. What would the
MSE be for this situation?
A) 196.00
B) 230.67
C) 175.00
D) 11.60
E) None of the above

27. Sales for boxes of Girl Scout cookies over a 4-month
period were forecasted as follows: 100, 120, 115, and
123. The actual results over the 4-month period were as
follows: 110, 114, 119, 115. What was the MAD of the
4-month forecast?
A) 0
B) 5
C) 7
D) 108
E) None of the above

33.
The diagram below illustrates data with a

A) negative
correlation coefficient.

B) zero
correlation coefficient.

C) positive
correlation coefficient.

D) correlation
coefficient equal to +1.

E) None of the above

36. A prediction equation for the number of people (in
1,000s) and the annual waste total (in metric tons) was performed using simple
linear regression. In the regression printout shown below, what can be said
about thelevel of significance for the overall model?
SUMMARY OUTPUT

Regression Statistics

Multiple R 0.715257514

R Square 0.511593311

Adjusted R Square 0.496330602

Standard Error 50.43909112
Observations 34

ANOVA
df SS MS F Significance
F
Regression 1
85276.17996 85276.17996 33.51917 1.99773E-06
Residual 32
81411.26122 2544.101913
Total 33
166687.4412

Coefficients Standard
Error t Stat P-value Lower
95%

Intercept 612.3757625
43.18367091 14.18072502
2.39E-15 524.4135038
# People 1.128638579
0.194943283 5.789574096 2E-06 0.731552108
????????????????????????
????????????????????????
A) Population size is not a good predictor for the amount of
waste.
B) The significance level for the intercept indicates the
model is not valid.
C) The significance level for population indicates the slope
is equal to zero.
D) The significance level for population indicates the slope
is not equal to zero.
E) None of the above

41. Describe the purpose and structure of a scatter diagram.
(Points : 4)

45. Demand for a particular type of battery fluctuates from
one week to the next. A study of the last six
weeks provides the following demands (in dozens): 4, 5, 3,
2, 8, 10 (last week).
Forecast demand for the next week using a two-week moving
average. (Round to nearest hundredth
4
46. Demand for a particular type of battery fluctuates from
one week to the next. A study of the last six
weeks provides the following demands (in dozens): 4, 5, 3,
2, 8, 10 (last week).
Forecast demand for the next week using a three-week moving
average. (Round to nearest hundredth)

47. Use simple exponential smoothing with ? = 0.3 to
forecast battery sales for February through May. Assume that the forecast for
January was for 22 batteries.

Month Automobile
Battery Sales Forecasted
Battery Sales
January42 ——-
February 33
March 28
April 59

48.
The following table represents the number of applicants at
popular private college in the last four years.

Month New members
2007 10,067
2008 10,940
2009 11,116
2010 10,999

Assuming ? = 0.2, ? = 0.3, an initial forecast of 10,000 for
2007, and an initial trend adjustment of 0 for 2007,use exponential smoothing
with trend adjustment to come up with a forecast for 2011 on the number of
applicants.

Forecast for 2011 = __________ (Fill in the blank with
correct answer)

49.
Using the diagram below. The predicted demand of 2014 using
the regression model is (Round
answer to nearest whole number)

50.
George Crowder is conducting research on monthly expenses
for a waste management company. His dependent variable is annual waste in
metric tons while his independent variable is number of people (in thousands)
that live in 25 selected cities. Below is his Excel output.

A) What is
the prediction equation for the annual metric tons of waste based on the
population?
B) Based on
his model, each additional (1000) increase in people the predicted waste in
metric tons is increased by how much?
C) Based on
the significance F-test, is this model a good prediction equation?
D) What
percent of the variation in waste is explained by the size of the population?
E) Can the
null hypothesis that the slope is zero be rejected? Why or why not?
F) What is
the value of the correlation coefficient and what conclusions can you draw
about the model based on the correlation coefficient.