Using a mean and standard deviation calculator we can see that


We now calculate the standard error
![\begin{gathered} \text{ standard error }=\frac{s}{\sqrt[]{n}} \\ \text{Where} \\ s=\text{ the sample standard deviation} \\ n=\text{ the sample size} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/hdcihpy6x7oeljlr8mormvrinc77friku3.png)
In this case,
n = 32,
![\text{standard error = }\frac{1.8184}{\sqrt[\square]{32}}=\text{ 0.3215}](https://img.qammunity.org/2023/formulas/mathematics/college/kksexsvln66hj57ttegem5ksh0fqajpzvx.png)
We now calculate the critical probability p*


Next, we find the degree of freedom df

We can now find the critical value. The critical value is the t value having degrees of freedom equal to df and a cumulative probability equal to the critical probability (p*).
Using a t-score calculator, we find that the critical value is 2.040
We will now find the margin of error (ME)

confidence interval is = mean

Confidence interval is (6,75-0.6559, 6,75+0.6559)
Confidence interval is (6.0941, 7.4059).
This means that the professor is 95% certain that the average hour of sleep of each student falls within the interval (6.0941, 7.4059).