A teacher wants to see if a new unit on fractions is helping students learn. She has five randomly selected students take a pre-test and a post test on the material. The scores are out of 20. Has there been improvement? (pre-post)
Student: 1, 2, 3, 4, 5
Pre-test: 15, 14, 15, 19, 14
Post-test: 19, 13, 12, 20, 18
What is the point estimate of the population mean difference between the pre and post test?
A) -1
B) 0
C) Unknown
D) 1.96