The psychology department is gradually changing its curriculum by increasing the number of online course offerings. To evaluate the effectiveness of this change,

a random sample of n 5 36 students who registered for Introductory Psychology is placed in the online version of the course. At the end of the semester, all students take the same final exam. The average score for the sample is M 5 76.

For the general population of students taking the traditional lecture class, the final exam scores form a normal distribution with a mean of m 5 71.

a. If the final exam scores for the population have a standard deviation of s 5 12, does the sample provide enough evidence to conclude that the new online course is significantly different from the traditional class? Use a two-tailed test with a 5 .05.

b. If the population standard deviation is s 5 18, is the sample sufficient to demonstrate a significant difference? Again, use a two-tailed test with a 5 .05.

c. Comparing your answers for parts a and

b, explain how the magnitude of the standard deviation influences the outcome of a hypothesis test.