The expected value can be calculated with the formula
[tex]E(x)=x\cdot p(x)[/tex]Where p represents the probability, and x represents the new event.
Basically, we just have to find the probability of the 13 cars
[tex]p(x)=\frac{13}{25}=0.52[/tex]Then, we multiply by the numbers of cars x = 75.
[tex]E(75)=75\cdot0.52=39[/tex]