Sum of deviations from \\\\(50\\\\) is \\\\(-10\\\\)\\\\(\\Rightarrow \\sum(xi - 50) = -10\\\\) \\\\(\\sum x_i - 50\\sum1 = -10\\\\) \\\\(\\sum x_i - 50n = -10\\\\)\\\\(\ herefore y-50n=-10.....(1)\\\\)Sum of deviations from \\\\(46\\\\) is \\\\(70\\\\)\\\\(\\Rightarrow \\sum(x_i - 46) = 70\\\\) \\\\(\\sum x_i - 46\\sum1 = 70\\\\) \\\\(\\sum x_i - 46n = 70\\\\)\\\\(\ herefore y-46n=70.....(2)\\\\)Solving \\\\((1)\\\\) and \\\\((2)\\\\), we get\\\\(4n = 80\\\\) i.e. \\\\(n=20\\\\)Putting value of \\\\(n\\\\) in \\\\((1)\\\\), we get\\\\(y=990\\\\)Mean \\\\(= \\dfrac{\\sum x_i}{n} = \\dfrac{y}{n} = \\dfrac{990}{20} = 49.5\\\\)