Answer:
The first student, with 20 measurements, will have the more precise interval due to the larger sample size.
Step-by-step explanation:
Margin of error of a confidence interval:
The margin of error of a confidence interval has the following format:
In which z is related to the confidence level, s to the standard deviation and n to the sample size.
The margin of error is inversely proportional to the square root of the sample size, which means that a larger sample will lead to a lower margin of error, that is, to a more precise interval.
In this question:
One student will use 5 measurements, other 20. The first student, with 20 measurements, will have the more precise interval due to the larger sample size.