Question

You recently took a statistics exam in a large class. The instructor tells the class that the scores were Normally distributed, with a mean of 72 (out of 100 ) and a standard deviation of 12 . Your score was 90 . Your friend had a time conflict and took a course with another instructor. Your friend had a score of 75 on a test, with a mean of 60 and a standard deviation of 10 . What can you conclude? You and your friend ranked equally well. You clearly ranked better. Your friend actually ranked better. The tests cannot be compared.

Answer 1

Correct option:

you and your friend ranked equally well.

EXPLANATION:
=72

= 12

Your score: X =90

               So,

              Z = (90 - 72)/12= 1.50

Your friend's score: Y = 75

=60

= 10

               So,

              Z = (75 - 60)/10= 1.50

Both your score and your friend's score are same Z value.

So,

Correct option:

you and your friend ranked equally well.