A psychology professor of a large class became curious as to whether the students who turned in tests first scored differently from the general population of his students. The overall mean score on the test was 75 with a standard deviation of 10; the scores were approximately normally distributed. The mean score for his sample of early finishers (the first 20 students to turn in tests) was 79.

Now assume the question of interest is: do students who finish early score significantly higher than the general population? Use the .05 level (5%), and select the correct conclusion.

a) Reject the null hypothesis, results indicate the early finishers score higher

b) Reject the null hypothesis, results indicate the early finishers score lower

c) Reject the null hypothesis, results indicate the early finishers score differently in an unknown way

d) Fail to reject the null hypothesis, insufficient evidence to suggest a treatment effect

e) Fail to reject the null hypothesis, we have proven early finishers score the same as the general population