To determine the expected sales [tex]\( y \)[/tex] when the company spends [tex]\( \$150 \)[/tex] on advertising, we will use the given linear regression equation:
[tex]\[ y = 2.1x + 130 \][/tex]
Here, [tex]\( x \)[/tex] is the amount of money spent on advertising, which is [tex]\( \$150 \)[/tex].
Let's substitute [tex]\( x = 150 \)[/tex] into the equation:
[tex]\[ y = 2.1 \cdot 150 + 130 \][/tex]
First, perform the multiplication:
[tex]\[ 2.1 \cdot 150 = 315 \][/tex]
Next, add the result to 130:
[tex]\[ y = 315 + 130 \][/tex]
[tex]\[ y = 445 \][/tex]
Therefore, the expected sales when the company spends [tex]\( \$150 \)[/tex] on advertising is [tex]\( \$445 \)[/tex].
Thus, the correct answer is:
D. \$445
