Hantavirus is carried by wild rodents and causes severe lung disease in humans. A study $^{5}$ on the California Channel Islands found that increased prevalence of the virus was linked with greater precipitation. The study adds "Precipitation accounted for $79 \%$ of the variation in prevalence."
(a) What notation or terminology do we use for the value $79 \%$ in this context?
(b) What is the response variable? What is the explanatory variable?
(c) What is the correlation between the two variables?