To solve this, we can use a proportion based on the data recorded by the mayor.

The proportion of electric vehicles is calculated by dividing the number of electric vehicles by the total number of vehicles observed:

$\text{Proportion of electric vehicles} = \frac{8}{50} = 0.16$

Now, we can apply this proportion to the total number of vehicles in the town (4,000 vehicles):

$\text{Expected number of electric vehicles} = 0.16 \times 4000 = 640$

Thus, the mayor can expect 640 electric vehicles out of 4,000 vehicles in the town.

Would you like further clarification or details? Here are five related questions for deeper understanding:

1. What percentage of the vehicles in town are expected to be hybrid?
2. How many gas vehicles are expected in the town?
3. What is the expected number of diesel vehicles out of 4,000?
4. How could the proportion of electric vehicles change if more were purchased over time?
5. How would the result differ if the mayor observed 100 vehicles instead of 50?

Tip: Always ensure that proportions are correctly calculated from representative data to estimate larger populations effectively.