Hantavirus is carried by wild rodents and causes severe lung disease in humans. A recent study 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?