A random variable has the following distribution
 

$\mathrm{X} = {\mathrm{x}}_{\mathrm{i}}$	1	2	3	4
P$\left(\mathrm{X} = {\mathrm{x}}_{\mathrm{i}}\right)$	k	2k	3k	4k

The value of k and P(x < 3) are equal to 
 

Given 

Since $\sum \mathrm{P}(X={\mathrm{x}}_{\mathrm{i}})=1$

$$\begin{gathered} \Rightarrow \mathrm{k}+2\mathrm{k}+3\mathrm{k}+4\mathrm{k}=1 \\ \Rightarrow 10\mathrm{k}=1 \\ \Rightarrow \mathrm{k}=\frac{1}{10} \end{gathered}$$

Now

 $\begin{array}{rcl}\mathrm{P}(\mathrm{x}& <& 3)=\mathrm{P}(\mathrm{x}=1)+\mathrm{P}(\mathrm{x}=2)\\ & =& \mathrm{k}+2\mathrm{k}\\ & =& 3\mathrm{k}\\ & =& \frac{3}{10}\end{array}$