To calculate the probability of picking a yellow ball, you need to know two things:
- The total number of balls in the pile.
- The number of yellow balls in the pile.
The probability of picking a yellow ball can be calculated using the formula:
\[ \text{Probability(yellow)} = \frac{\text{Number of yellow balls}}{\text{Total number of balls}} \]
Once you have the values for the number of yellow balls and the total number of balls, substitute them into the formula to find the probability.
If you provide the numbers, I can help you calculate the probability as a decimal.