\[\boxed{\mathbf{47.}}\]
\[1)\ (1 + 2 + 3 + 4)\ :4 = 2,5\]
\[2)\ (2 + 3 + 4 + 5)\ :4 = 3,5\]
\[3)\ (3 + 4 + 5 + 6)\ :4 = 4,5\]
\[4)\ (10 + 11 + 12 + 13)\ :4 =\]
\[= 46\ :4 = 11,5\]