To find the probability of selecting an even number using the uniform probability model for numbers 1 to 9, we first need to identify the even numbers in this range. The even numbers between 1 and 9 are: 2, 4, 6, and 8.
Since there are 9 total numbers (1 through 9) and they are equally likely to be selected, the probability of selecting any specific number is:
\[ \text{Probability of each number} = \frac{1}{9} \]
Next, we count the even numbers:
- Even numbers: 2, 4, 6, 8 (Total = 4 even numbers)
Now, we calculate the probability of selecting an even number:
\[ \text{Probability of selecting an even number} = \frac{\text{Number of even numbers}}{\text{Total numbers}} = \frac{4}{9} \]
Thus, the correct response is:
\(\frac{4}{9}\).