A random variable $X$ has the following probability distribution:

$X=x$	$1$	$2$	$3$	$4$
$P\left(X=x\right)$	$k$	$2k$	$3k$	$4k$

The value of $P(X<3)$ is

$X$ is a continuous random variable with probability density function $f\left(x\right)=\left\{\begin{array}{l}\frac{x^2}{8}; 0\le x\le 1\\ 0; \text{otherwise}\end{array}\right.$. Then, the value of $P\left(0.2\le X\le 0.5\right)$ is

For the probability density function $f\left(x\right)=\left\{\begin{array}{lr}2e^{-2x},& x>0\\ 0,& x\le 0\end{array}\right.$

$F\left(2\right)$ is equal to