There is no graph to support the statement and so, this invisible graph is misleading :)
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.
So for a tangent and a secant, you multiply x^2 (since it’s a tangent you square it) and test that equal to 6(6+12) so now you have x^2=6(6+12). solve for X to get sqrt(108) or 10.4
the equation is — tan^2=outside x whole thing
remember to ADD the entire secant (so add 6 plus 12) don’t multiply them (6x12)
x^2=6(6+12)
x^2=6(18) OR x^2=36+72
x^2=108
x=sqrt(108) OR x=10.4
u = 19
Hope this helps, Good luck! (: