To determine the experimental probability of choosing a blue marble from Marnie's experiment, we follow these steps:
1. Identify the total number of trials: According to the table, Marnie conducted 20 trials in total.
2. Identify the number of successful events: The table indicates that Marnie chose a blue marble 7 times.
3. Calculate the experimental probability:
- The formula for experimental probability is given by the number of successful events divided by the total number of trials.
- Here, the number of successful events (blue marbles chosen) is 7, and the total number of trials is 20.
[tex]\[
\text{Experimental Probability} = \frac{\text{Number of Successful Events}}{\text{Total Number of Trials}} = \frac{7}{20}
\][/tex]
So, the experimental probability of choosing a blue marble from the bag is:
[tex]\[
\frac{7}{20}
\][/tex]
Therefore, the correct answer is [tex]\(\frac{7}{20}\)[/tex].
