Answer:
True
Step-by-step explanation:
The margin of error of a confidence interval is given by:
[tex]M = z*\frac{\sigma}{\sqrt{n}}[/tex]
In which z is the critical value related to the confidence level, [tex]\sigma[/tex] is the standard deviation of the population and n is the size of the sample.
So as n increases, the margin of error decreases, that is, the interval gets narrower.
The students could produce a narrower confidence interval by increasing the sample size to 100.
From the explanation above, the answer is true.