a test of abstract reasoning is given to a random sample of students before and after they completed a formal logic course. The results are below. Construct a 95% confidence interval for the mean difference between the before and after scores. Is there evidence to suggest the logic course improves abstract reasoning? You may assume that the differences for the dependant samples are normally distributed.
before 74 83 75 88 84 63 93 84 91 77
after; 73 77 70 77 74 67 95 83 84 75
Note; define d= before -after, then d = 3.7 and s = 4.95
2007-11-17 02:39:22 · 1 answers · asked by Eugene D 1 in Science & Mathematics ➔ Mathematics
This is a statistical question. You need to perform a t test to see if there is a statistically significant difference between the two populations (to 95% confidence). A statistical analysis program such as Minitab will easily do the math. It can also be done in a spread sheet program such as Excel.
Just by inspection the std dev of the before group looks to be ~ 5, std dev for after is ~ 4.7, so there is not much difference in the variability between groups. The full statistical analysis will determin if the means are different by enough to be statistically significant to 95% confidence. good luck
2007-11-17 02:49:50 · answer #1 · answered by Gary H 7 · 0⤊ 0⤋