Using the z-distribution, the observed test statistic is given as follows:
z = 3.69.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis, it is tested if older students have the same mean as the general population, that is:

At the alternative hypothesis, it is tested if they have a greater mean, that is:

<h3>What is the test statistic?</h3>
The test statistic is:

In which:
is the sample mean.
is the value tested at the null hypothesis.
is the standard deviation of the population.
For this problem, the parameters are:

Hence the test statistic is:


z = 3.69.
More can be learned about the z-distribution at brainly.com/question/25890103
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