The average score of 100 students taking a statistics final was 70 with a standard deviation of 7. Assuming a normal distribution, approximately how many scored less than 60?
A) 0.2271
B) 0.3729
C) 0.8929
D) D)-1.14
E) None of the choices are correct

Question

Quizplus · Accepted Answer

The z-score for a score of 60 is (60-70)/7 = -1.43. Using the standard normal distribution table, the probability of a z-score being less than -1.43 is approximately 0.0764. Therefore, approximately 7.64 students scored less than 60, which does not match any of the given choices.

The Average Score of 100 Students Taking a Statistics Final