The probability distribution of a random variable X is given below: If E ( X )=263/15, then P ( X <20) is equal to:

The probability distribution of a random variable X is given below :

X	4k	$\displaystyle \frac{30}{7} \mathrm{k}$	$\displaystyle \frac{32}{7} \mathrm{k}$	$\displaystyle \frac{34}{7} \mathrm{k}$	$\displaystyle \frac{36}{7} \mathrm{k}$	$\displaystyle \frac{38}{7} \mathrm{k}$	$\displaystyle \frac{40}{7} \mathrm{k}$	6k
P(X)	$\displaystyle \frac{2}{15}$	$\displaystyle \frac{1}{15}$	$\displaystyle \frac{2}{15}$	$\displaystyle \frac{1}{5}$	$\displaystyle \frac{1}{15}$	$\displaystyle \frac{2}{15}$	$\displaystyle \frac{1}{5}$	$\displaystyle \frac{1}{15}$

If $\displaystyle \mathrm{E}(\mathrm{X})=\frac{263}{15}$, then $\displaystyle \mathrm{P}(\mathrm{X}<20)$ is equal to :