To create a probability model for the experiment of picking a card from the number cards 2, 4, 6, and 10, we first note that there are four equally likely outcomes. Therefore, the probability of picking any one specific card is the same for all cards.
The total number of cards is 4, and each card is equally likely to be picked. The probability \( P(x) \) of picking any card \( x \) (where \( x \) can be 2, 4, 6, or 10) is given by the formula:
\[ P(x) = \frac{1}{\text{Number of outcomes}} = \frac{1}{4} \]
Thus, the probability model can be expressed as:
\[ f(x) = \frac{1}{4}, \quad \text{where } x = 2, 4, 6, 10 \]
So the answer is:
\[ f(x) = \frac{1}{4}, \text{ where } x = 2, 4, 6, 10 \]