Use your statistical package to create new variables consisting of the z scores for the anxiety and heart rate measures both at baseline and prequiz in Ihno's data set. Request means and standard deviations of the z-score variables to demonstrate that the means and SDs are 0 and 1, respectively, in each case. If, like SPSS, your statistical software computes only s for the standard deviation and not σ, you should calculate your z scores based on s.