of the 50 students in the cafitera, 7 have red hair. If there are 750 students in the school, predict the number of students who have red hair.

So first, start with a ratio.
7:50
7 being those with red hair, to the 50 students.
There are 750 students total, so to get there multiply each side of the ratio by 15.
105:750

Therefore, a prediction you could make is that 105 students have red hair.