Mali noticed that the observed frequencies did not match the predicted frequencies. What does she need to change in her experiment to get closer to the predicted values based on the theoretical probability for all the face cards?

Observed frequencies tend to get closer to theoretical probabilities when the number of trials increases. More trials reduce the effect of random variation, so the results are more likely to approach the predicted frequency for face cards. A new deck or using only number cards would change the experiment rather than improve the match.

AI-written and checked against the verified answer.