“…The subject of Backus average was examined by several researchers, among them, Helbig and Schoenberg (1987), Schoenberg and Muir (1989), Berryman (1997), Helbig (1998Helbig ( , 2000, Carcione et al (2012), Kumar (2013), Brisco (2014), and Danek and Slawinski (2016). However, further venues of investigation remain open.…”