is ziq a covariate which iq test is an appropriate way to account for a covariate what is the relationship between iq and head size in research why is zIQ used z-standardization iq what is zstandardization used for what test is best to account for hq which test measures iq which of the following is an example of zq? why is the z-standardization of iq necessary for a covariate? what is the relationship between iq and head size? qig z standardization what is the z standard iq what is zstandardization when iq is standardized is it appropriate is ziq considered a covariate iq as a covariate how is zscore used does z iq include covariates does ziq include the iq scale is z-standardization appropriate