1. Using the correlation matrix below, is there a direct correlation between satisfaction with sex life (satisfaction, Y) and the number of years the person has been married (years, X), controlling for frequency of sex (frequency, Z)? (By the way, yes, this is what research finds on this topic!)

Satisfaction () Years Married (X) Frequency (Z) Satisfaction () 1.00 0.53 0.18 Years Married (X) 1.00 -0.19 Frequency (Z) 1.00