Question

Question 1:

TAs are in the midst of marking midterm 3. The professor is curious about how the students have performed. The professor thinks they obtained 70% and knows from prior times he's taught the course that the variance in the grades is 25. If a random sample of 9 papers has a mean grade of 73% what is the corresponding discrepancy?

A) -1.8

B) 1.8

C) -3

D) 3

E) None of the above

Answer 1

Answer)

Discrepancy = (x - mean)/(s.d/√n)

N = 9

S.d = √25

X = 73

Mean = 70

After substitution

Answer is 1.8