Can Categorical Variables be Used in Multiple Regression Models?

[smp]

Hello, I am trying to do the following regression model;

Y = N + T + F + NT + NF + NTF + error

Y= Grams of seed
N= Number of fruit
T= Type of fruit (2 types, alpha)
F= Field number (3)

I have tried putting this in MiniTab and I can't get this set up correctly.
Assistant> Regression> Multiple Regression

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Y= Grams of Seed

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Continuous X Variable= Number of Fruit, Field Number - but I can't select Type since they are words and not numbers. .

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Categorical X value is optional- should I put Type here?

Thank You

 

[I like Serena]

Hi smp, welcome to MHB!

This looks like a trick question.
We can indeed not add a type and number together. That is, it is not possible to evaluate something like "apple" + 2.
More generally, a multiple linear regression requires that all variables are quatitative (interval or ratio). That excludes categorical.