Using it's concept, the experimental probability that in a group of 4 students, at least one of them has green eyes is of 0.45 = 45%.
<h3>What is a probability?</h3>
A probability is given by the <u>number of desired outcomes divided by the number of total outcomes</u>. An experimental probability is calculated considering the results of previous trials.
In this problem, there were 20 trials. The digit 9, which represents a student with green eyes, appears at least once in 9 of the the trials, hence the probability is: