7. We consider that the results obtained by students in administrative sciences, for a test of aptitude in management computing, are distributed according to a normal distribution of variance, s2 = 225. For a random sample of 25 students, the average score is 70.6. Estimate by confidence interval, the upper limit of this interval for the mean score of all students in administrative sciences with a confidence level of 90%.

a) 78,33

b) 76,48

c) 75,53

d) 74,92

e) 74,44