If one out of every five Americans suffers from allergies, then the proportion of Americans who suffer from allergies is $\frac{1}{5}$. 
To find the number of Americans in the sample who would suffer from allergies, we multiply the proportion by the total number of Americans in the sample. 
So, we have $\frac{1}{5} \times 250 = \frac{250}{5} = 50$. 
Therefore, we would expect 50 Americans in the sample to suffer from allergies.The answer is: 50
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
One out of every five Americans suffers from allergies. In a random sample of 250 Americans, how many would you expect to suffer from allergies?

### Answer:
