stat assignment

Spring 2021

ECO 578 Journal Article

Sample Data for Supermarket Profits

Supermarket

Number

Food Sales (tens

of thousands of

dollars)

𝑿𝟏

Nonfood Sales

(tens of thousands

of dollars)

𝑿𝟐

Store Size

(thousands of

square feet) 𝑿𝟑

Profit (thousands

of dollars) Y

1 305 35 35 20

2 129 98 20 15

3 189 83 27 17

4 175 76 16 9

5 101 93 28 16

6 269 77 46 27

7 425 44 58 35

8 195 47 12 7

9 282 31 40 22

10 203 92 32 23

You have to indicate the purpose of the study and discuss (not listing) data characteristics

before answering questions and interpreting the results of the regression analysis.

1. Run a multiple regression using the above data. (with profit as the dependent variable).

2. Compare the result of question (1) with another regression equation obtained without the food

sales variable.

3. Which of the models do you prefer? Why?

4. Interpret your results for (1) and (2).

5. In writing your paper, you should start by indicating the purpose of the study. Also, discuss the

methodology and conclusions.

Spring 2021

** You can use EXCEL or any other software. ** You need to include your printout in your

submissions.

The layout and format of the paper should include the following sections:

Title page, Abstract, Introduction, Method, Results, and Discussion.

a) Abstract is a very concise summary of the paper.

b) The Introduction tells the reader about the topic. Specifically, it should start with the

purpose of this paper is to examine…. What the issue is, what is known about it, and the specific

focus? Put a business context to it -- write the value added by your work or what businesses can

gain from the knowledge of the determinants of market profits.

c) Empirical Results you should start with a brief discussion of the descriptive statistics for

each variable.

d) Method you should be able to explain what method you are using for your work. For

example, you can start with telling the reader that the ordinary least squares method (OLS) was

used to obtain estimated coefficients... (Then write more). You should be able to write the equation

from the Excel result. We expect to see you… 1. Using the excel result to generate the equation.

2. Find the standard error of each variable.

3. Find the t-stat of each variable.

4. Find the p-value of each variable.

Spring 2021

EXAMPLE:

Ŷ = 1.24 + 1.71x1 - 0.83x2 - 2.12x3

𝐒𝐛𝟏 (6.79) (1.43) (0.22) (0.85)

T-stat [0.18] [1.20] [3.78] [2.48]

P-value 0.857 0.247 0.002 0.025

e) The results section should tell what was found from the computed data. Using Chapter 10

and 11 for helping you interpret your result. For instance, you should interpret the Coefficient of

Determination (R!), F-test, t-test, p-value and etc. In addition, your result should use the hypothesis

equation.

Remember that in the results section there should include hypothesis testing for a t-test about

each slope coefficient and a F-test for the overall regression model.

EXAMPLE:

For the t-test, it is written like this:

H":

H$: β# ≠ 0

Note:

You have to decide whether to use one-tail or two-tail test

You need to follow chapter 9 materials and declare your alternative hypothesis in each

case very well

F-test:

H":

H$: , or all three are ≠ 0

(Note that: remember to mention what α is used in your hypothesis testing).

Spring 2021

f) The Discussion describes what your findings mean in the light of the information presented

in the introduction. It is the interpretive segment of the paper and loops back to answer the issues

raised in the introduction. Remember to answer questions 2 and 3.