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Question: Write a regression model relating the mean value of y to a qualitative independent variable that can assume two levels. Interpret all the terms in the model.

Short Answer

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Answer:

Regression model for one qualitative independent variable with two level isx1=(1IFyisobservedatleveli+10otherwise) .Hereβ0denotesμxithe mean for base levelβ1andβ2denotes difference between the mean levels for different dummy variables. While,x1andx2denotes different levels of dummy variables used in the model which can take value of either 0 or 1.

Step by step solution

01

Regression model for one qualitative independent variable

A regression model relating the mean value of y to a qualitative independent variable that can assume two levels can be written as

E(y)=β0+β1x+β2x2

Where, x1 is the dummy variable for i+1level

Meaning x1=(1IFyisobservedatleveli+10otherwise)

02

Interpretation of the terms in the model

Hereβ0denotesrole="math" localid="1649848061325" μxithe mean for base level

β1andβ2denotes difference between the mean levels for different dummy variables.

While,role="math" localid="1649848167521" x1and role="math" localid="1649848182825" x2denotes different levels of dummy variables used in the model

which can take value of either 0 or 1.

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