I have 2 groups (n=11 each). Looking at IQ scores... I need to compare the 2groups to see if there are differences along 4 different variables. I finally figured out that the assumptions of normality are not met due to heterogeneity of variance (as well as small sample size)... so I think I'm supposed to use non-parametic analysis, mann-whitney. Am I on track so far?

I also want to compare my experiemental group to the norm population (mean=100, SD=15) to see if my experiemental group is significantly different along each of the IQ variables. I think I'm supposed to do something called a z-test for this.

Is the Z test the same as : sample mean-population mean/SE? (which I thought was called a Z-score)

Since my data is not normally distributed, can I still use a z-test to look at the 2 groups? Is there a way to do a z-test on SPSS? If a Z-test is not appropriate here, what else can I use to compare my experimental group to the norm population...

I'd appreciate any clarification...