4 (25 pts).Download thefile "GRE workshop" file. The file shows the GRE scores of 40 participants before and after the workshop. The GRE workshop wants to know whether the workshop improves participants' GRE scores.

Use SPSS to do the following:

(a) Find the sample means and sample standard deviations before and after the workshop.

Paired Samples Statistics
	Mean	N	Std. Deviation	Std. Error Mean
Pair 1	Before_workshop	148.53	40	7.575	1.198
After_workshop	152.57	40	6.288	.994

(b) At