A mammalogist is studying the diving behavior of a species of dolphin. The depth \( D(t) \) in meters that a dolphin reaches after \( t \) seconds is modeled by \( D(t) = pt^3 + qt^2 + rt + s \). Given \( D(1) = 3 \), \( D(2) = 14 \), \( D(3) = 39 \), and \( D(4) = 84 \), find the coefficients \( p \), \( q \), \( r \), and \( s \). - Crosslake