Answer:
The sample size should be 273 students
Step-by-step explanation:
Here Raina wants to use 90% interval then
ME = z. SE
SE = s d/√n at end
ME/z = s d/√n
n={z.sd/ME)²
Z = 1.65 =>due to 90%confidence interval
ME= 24
sd=250
putting these value in the question we get 273 students