Question

1. A pre-test was given to a group of students at the beginning of the semester with regard to their statistics knowledge. The same group of students was given a post-test on the same subject matter at the end of the semester. The table below shows the students pre- and post-test scores. The main question of interest is whether or not there was significant improvement in statistics knowledge over the course of the semester. First, calculate the difference score for each student and then calculate the mean, sum of squares, variance, standard deviation, and standard error of the difference scores. Please put your answers in the spaces provided and show work for your hand calculations. Student Pre-test Post-test Difference Joe 5 2 Linda 3 7 Tim 1 3 John 1 2 Mike 2 4 Fran 2 6 Andrea 2 5 Kelly 3 1 Keith 4 9 Joan 2 6 Mean = Sum of Squares = Variance = Standard Deviation = Standard Error = 5. What are the degrees of freedom for this analysis? 7. Check the assumption that the difference scores are normally distributed. Is this assumption met? How do you know? 8. Is there a statistically significant difference between pre and post-test scores. How do you know?

Answer 1