An analyst uses the data set in the Excel file to study the relationship between Demand $($the dependent variable$)$ and the two independent variables: Price and Advertisement. He fits a First Order Model and discovers that the residual plot against Price shows a clear trend. Hence, he calculates the Partial Regression Residuals for Price as follows:$$P$.$R$.$R$.$

PRICE $($X$1)$

$-1403\mathrm{.}1$

$$3\mathrm{.}60$

$-1486\mathrm{.}1$

$$3\mathrm{.}80$

$-1597\mathrm{.}1$

$$4\mathrm{.}00$

$-1672\mathrm{.}1$

$$4\mathrm{.}20$

$-1759\mathrm{.}1$

$$4\mathrm{.}40$

$-1797\mathrm{.}1$

$$4\mathrm{.}60$

$?$

$$4\mathrm{.}80$

$-1410\mathrm{.}4$

$$3\mathrm{.}60$

$-1493\mathrm{.}4$

$$3\mathrm{.}80$

$-1583\mathrm{.}4$

$$4\mathrm{.}00$

$-1680\mathrm{.}4$

$$4\mathrm{.}20$

$-1753\mathrm{.}4$

$$4\mathrm{.}40$

$-1816\mathrm{.}4$

$$4\mathrm{.}60$

$-1865\mathrm{.}4$

$$4\mathrm{.}80$The missing value marked as $?$ should be:

a$.-$$$1,604\mathrm{.}5$

b$.-$$$1,868\mathrm{.}1$

c$.-$$$1,888\mathrm{.}1$

d$.$ $$1,604\mathrm{.}5$