Consider the following exponential probability density function.

$f(x)=\frac{1}{4}{e}^{-\frac{x}{4}},$ for $x0$

$($a$)$ Write the formula for $P(x{x}_0).$

$P(x{x}_0)=$

$($b$)$ Find $P(x2).($Round your answer to four decimal places.$)$

$($c$)$ Find $P(x4).($Round your answer to four decimal places.$)$

$($d$)$ Find $P(x6).($Round your answer to four decimal places.$)$

$($e$)$ Find $P(2x6).($Round your answer to four decimal places.$)$