Using the $4-$variable linear equation, for each year the marranty is increased, me company's sales is expected to:

a$.$ Increase by $$3,801$

b$.$ Decrease by $$3,801$

c$.$ Increase by $$278\mathrm{.}4$

d$.$ Decrease by $$270\mathrm{.}1$

Using the $4-$variable linear equalion, the estimated saies for the following condtions acturining expendiure of $$400,$ zero competitor, $3$ discounts, and $1$ year of warranty $-$ will be $($we the closent value$)$:

$7,95,498$

b$.55,320$

c$.$ $$3,461$

Uning a signiticarice level of $0\mathrm{.}01,$ is the $4-$variable linear model signillow?

a$.$ Yes

b$.,No$