Question: Download the data set histidine.sav and use it to answer the research question: "Is there a mean difference in the 24-hour histidine excretion among men and women?" Use SPSS to complete the following calculations:
(a) Run a two-sample independent t test.
(b) Calculate a 95% CI for the mean difference in the 24-hour histidine excretion levels among men and women.

For question #1, comment on which version of the t test we should use (equal variance or unequal variance) and why?