Modeling Nonlinearities and Interactions

Hi,

When we analize data with representents groups of data or variables, we find that changes in the INDEPENDANT VARIABLE often influences a DEPENDANT VARIABLE throu a nonliniear relationship. That means when we yields a shift in the dependant variable caused by a unit of change in the independant variable, the ratio of this change in not constant.


You could see more details of this calculation by clicking here.
 

Incorporating Qualitative Factors into Multiple Regression

Hi,

In this lesson I learnt: how can I predict quarterly U.S. auto sales?

Suppose we want to predict quarterly U.S. auto sales to determine whether the quarter of the year impacts auto sales. We'll use the data in the file you could click below, where sales are listed in thousands of cars, and GNP is in billions of dollars.

Click here to see how I made the analysis.

Introducing to Multiple Regression

Hi,

In this lesson I learnt the meaning of the parameters (Coeficients, p-vauleu, R2, Standard error...) that could influence in a multiple regression, how I can trust in the forecast made from the equation build with the coeficients, how much accurate we'll be our predictions...


Click here

Using Correlations to Summarize Relationships

Hello,


In this chapter I learnt to read this statistic tool: correlation, to know the degree of relation between two variables, that means by using this took we are able to know how much is the shift behavior of each other.


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The Power Curve: a curve where takes place production and learning by doing

Hi everybody,

The Power Curve (y = Ax^b) is a shape where it fits the dates from production cost as a function of units produced (frequently b>1), or dates from sales as a function of advertising expenditures (usually -1
You could see some examples by clicking here 

Forecasting by using Straight Line Relationships

Hi again,

Every business analyst should have the ability to estimate the relationship between important business variables. The trend curve, which I discuss in this Excel fileif often helpful in determining the relationship between two variables. The variable that analyst try to predict is called the dependent variable. The variable we use for prediction is called the independant variable.

It is nice to see as we could forecast the behavior of the independant variable throughtout our decisions in the dependant variable. We could see how it's apply in the Excell file presented below.



Click here

Summarizing Data with Database Statistical Functions

Dear alls,

Dear friends

This chapter I learnt to get specific data from a database summarizing and sorted by using some EXCEL BDFUNCTIONS. As we know a database is made up off fields where it contains data, we could get these data classified and sorted by summarizing, counting, averaging... following the approaches we defined.


If you like to look at click here