In the presented paper, Levinson's inequality for 3-convex function is generalized by using two Green's functions.Čebyšev, Grüss, and Ostrowski-type new bounds are found for the functionals involving data points of two types. Moreover, the main results are applied to information theory via f-divergence, Rényi divergence, Rényi entropy, Shannon entropy, and Zipf-Mandelbrot law.