Let be the number of students who eat cauliflower.
Therefore, .
Let be the total number of students surveyed.
Therefore,
Thus,
Now, for 90% confidence level, from the table we know that .
The formula for the interval range of proportion of students is :
Plugging in the values we get:
Thus, Jane is 90% confident that the population proportion p, for students who eat cauliflower in her campus is between 5.398% and 15.114% (after converting the answer we got to percentage).