When using best subsets regression with a model that has four independent variables, a total of different combinations of regression models will be considered. a. 4
b. 15
c. 12
d. 18

b. 15

Step-by-step explanation:

Given that:

There are 4 independent variables, then the subset regression total is 2⁴ = 16 attainable regression model.

However, out of these 16 regression models, 1 Model contains no predictors which only intercept 3 Model with , 3 Model with. and 1 Model which comprises all the independent variables.

Therefore, when applying best subsets regression with a model that possesses four (4) independent variables, the number of different combinations of regression models that can be considered is 15.

20/27

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step-by-step explanation:

1 simplify brackets

-\frac{8}{9}\times \frac{5}{6}−

​9

​

​8

​​ ×

​6

​

​5

​​

2 use this rule: \frac{a}{b}\times \frac{c}{d}=\frac{ac}{bd}

​b

​

​a

​​ ×

​d

​

​c

​​ =

​bd

​

​ac

​​

-\frac{8\times 5}{9\times 6}−

​9×6

​

​8×5

​​

3 simplify 8\times 58×5 to 4040

-\frac{40}{9\times 6}−

​9×6

​

​40

​​

4 simplify 9\times 69×6 to 5454

-\frac{40}{54}−

​54

​

​40

​​

5 simplify \frac{40}{54}

​54

​

​40

​​   to \frac{20}{27}

​27

​

​20

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