Answer:
The width of the 95% confidence interval for p is 0.2496
Explanation:
Taking into account that the proportion of the students from the sample that prefer the taste of fresh-brewed coffee is calculated as:
p' = 35/60 = 0.5833
Because there are 60 students in the sample and 35 prefer the taste of fresh brewed coffee.
So, the width of the 95% confidence interval for p is calculated as:

Where n is the number of the students in the sample and 1.96 is the z values that satisfy that:
2P(Z>1.96) = 1 - 0.95 = 0.05
Then, replacing p' by 0.5833 and n by 60, we get:

Finally, the width of the 95% confidence interval for p is 0.2496