Data collected from a single entities across a given period called:

A. Cross-sectional data

B. Time series data

C. Categorical and quantitative data

D. Random data

E. None of the choices

2. Which of the following coefficient indicates the highest correlation between two variables:

A. -0.95

C. 0.90

E. None of the choices

3. In a(n) ________________, one or more variables are identified and controlled or manipulated so that data can be obtained about how they influence the variable of interest identified first.

A. Observational study

B. Experimental study

C. Regression study

D. Variable study

E. None of the choices

4. In linear regression analysis the quantity that gives the amount by which the dependent variable changes for a unit change in the independent variable is called the

A. standard error

B. slope of the regression line

C. correlation coefficient

D. coefficient of determination

E. none of the choices

Problems 5-7 are based on the following:

The business analyst for Video Sales, Inc. wants to forecast this year's demand for DVD decoders based on the following historical data: Year: Demand:

5 years ago 900

4 years ago 700

3 years ago 600

2 years ago 500

last year 300

5. What is the forecast for this year using the naive approach? A. 100 B. 180 C. 300 D. 420 E. None of the choices

6. What is the forecast for this year using a three-year moving average? A. 163 B. 180 C. 300 D. 467 E. None of the choices

What is the forecast for this year using exponential smoothing with alpha = .4? A. 639 B. 180 C. 300 D. 504 E. None of the choices

Simple exponential smoothing is being used to forecast demand. The previous forecast of 66 turned out to be four units less than actual demand. The next forecast is 66.6, implying a smoothing constant, alpha, equal to: A. 0 .01 B. 0.10 C. 0.15 D. 0 .20 E. None of the choices

Given forecast errors of 5, 0, 4, and 3, what is the mean absolute error? A. 4 B. 3 C. 2.5 D. 1 E. None of the choices

Problems 10-16 are based on the following:

The CIO of an IT company would like to investigate how a software developers work experience, professional certifications, and knowledge of various computer languages, contribute to his/her work performance. He collects the following data from 20 software developers in his company:

the number of years one has worked (Years of experience)

the number of professional certificates one has received (Num of certificates)

the number of programming languages (e.g. Java, C#,) that one knows (Num of ProgLang)

Ones work performance score (Performance). The higher ones score, the better his/her work performance.

The CIO runs a regression model to test the effect of these factors on ones work performance. The data and the regression output is given below.

Employee ID	Years of experience	Num of certificates	Num of progLang	Performance
1	27	3	8	880
2	11	1	2	686
3	6	2	1	681
4	21	3	4	877
5	26	3	4	975
6	21	3	4	902
7	18	3	3	900
8	15	2	5	882
9	x	2	3	775
10	5	y	3	650
11	17	2	z	908
12	14	2	4	687
13	15	3	4	891
14	7	2	3	566
15	5	3	1	959
16	13	2	5	793
17	11	2	4	778
18	31	3	7	975
19	16	2	5	846
20	12	3	6	779

SUMMARY OUTPUT
Regression Statistics
Multiple R	0.805
R Square	XX
Adjusted R Square	0.58
Standard Error	75.51
Observations	20

ANOVA
	df	SS	MS	F	Significance F
Regression	3	168001	56000	XX	0.001
Residual	16	91223	5701
Total	19	259225
	Coefficients	Standard Error	t Stat	P-value	Lower 95%	Upper 95%
Intercept	556.83	67.11	8.30	0.00	414.56	699.09
Years of experience	9.26	3.78	XX	0.03	1.26	17.27
Num of certificates	82.20	31.91	XX	0.02	14.56	149.84
Num of progLang	-17.58	13.81	-1.27	XX	-16.87	11.70

10. What is calculated value of the t-test statistic for the Years of experience variable?

A. 8.30

B. 2.45 9.26/3.78

C. 3.23

D. 6.59

E. None of the choices

11. What is calculated value of the F-test statistic?

A. 8.70

B. 2.45

C. 9.82

D. 6.59

E. None of the choices

12. What is the R-Square of the regression model?

A. 0.648

B. 0.250

C. 0.160

D. 0.930

E. None of the choices

13. The CIO wants to predict the performance of a job applicant that has 16 years of work experience, holds 3 certificates, and knows 2 programming languages. Based on the regression output, what is the predicted performance?

A. 996

B. 916

C. 900

D. 856

E. None of the choices

14. Which of the following predictors were found to be significant at 0.05 significance level?

A. Num of certificates and Num of progLang

B. Years of experience and Num of progLang

C. Years of experience and Num of certificates

D. Years of experience, Num of certificates, and Num of progLang

E. None of the choices

15. Which statement is correct at 0.05 significance level?

A. Accept the hypothesis for T-test in Num of progLang

B. Accept the hypothesis for T-test in Num of certificates

C. Accept the hypothesis for T-test in Year of Experience

D. Accept the hypothesis for F-test

E. None of the choices

Quarter Enrollments in Business Statistics course at a major university are given in the EXCEL worksheet Enrollment. Answer the following questions.

Develop a model for trend and seasonality. Please clearly define your variables.

Use the model to forecast for the enrollments for Fall 2013, Winter 2014, and Spring 2014.

What is the MSE for this forecast?