32 students would be on the trip. What I did to solve it was a proportion. 8students/ 3 chaperones= x students/12 chaperones.
8*12= 96 and 96/3=32. Therefore 32 students were on the trip.
Answer:

we can conclude at 95% of confidence that the true proportion of interest for this case is between 0.287 and 0.613
Step-by-step explanation:
The estimated proportion of interest is 
We need to find a critical value for the confidence interval using the normla standard distributon. For this case we have 95% of confidence, then the significance level would be given by
and
.
And the critical value is:
The confidence interval for the true population proportion is interest is given by this formula:

Replacing the values provided we got:

And we can conclude at 95% of confidence that the true proportion of interest for this case is between 0.287 and 0.613