$(15$ points$)$ For the population of chief executive officers $($CEO$),$ let salary be annual salary in millions of dollars, and let roe be the average return on equity for the previous three years. Return on equity $($roe$)$ is defined in terms of net income as a percentage of common equity. For example, if roe $=10,$ then average return on equity is $10\%.$ Using the data, the OLS regression line relating salary to roe is

sal$y=1\mathrm{.}25+0\mathrm{.}33$ roe

$n=209,R^2=0\mathrm{.}213$

$($a$)$ Interpret the intercept clearly.

$($b$)$ Interpret the slope estimate clearly.

$($c$)$ Explain the meaning of $R^2=0\mathrm{.}213$ clearly