In the given figure we can observe a diagram of voltage levels vs P(x).
The probability a random coltage is lees than 124.2 volts is given by the area of the square under 124.2.
A diagram of the situation is:
The area of a rectangle is given by the formula:
[tex]A=W*L\rightarrow W=width,L=length[/tex]
The width and length of this rectangle are:
[tex]\begin{gathered} W=124.2-123.0=1.2 \\ L=0.5 \end{gathered}[/tex]
So, the area is:
[tex]A=1.2*0.5=0.6[/tex]
Thus, the probability a random voltage is less than 124.2 is 0.60
