To find the average of a number (let's denote it as $x$) and 4, you would use the following formula:

$\text{Average} = \frac{x + 4}{2}$

So, the average of the number $x$ and 4 is $\frac{x + 4}{2}$.

Would you like further details or have any questions?

Here are some related questions:

1. What is the average of two different numbers?
2. How do you calculate the average of three numbers?
3. If the number $x$ is 8, what is the average with 4?
4. What is the average if $x$ is a negative number?
5. How does changing $x$ affect the average?
6. Can you find the average if $x$ is a fraction?
7. What happens if both numbers are the same?
8. How do you calculate the average of more than two numbers?

Tip: The average of two numbers is always a value between those two numbers.