Answer:
30
Explanation:
It is better to include 30 students for the sample. When conducting an experiment it is always best to have the largest sample size possible. The larger the sample size the more data that will be gathered and analyzed, which ultimately leads to much more precise results. Mainly, since you have more results to compare with one another. Therefore, providing a smaller margin of error while also allowing for a better chance of catching errors as opposed to smaller data/sample sizes.