Question 1044326
Here are the new sets after a non-negative single-digit integer was added to X:
The median of X is 5 and its range is 6.

{ 0,2,3,7,8 } ===> median is 3, range is 8
{ 1,2,3,7,8 } ===> median is 3, range is 7
{ 2,2,3,7,8 } ===> median is 3, range is 6
{ 2,3,3,7,8 } ===> median is 3, range is 6
{ 2,3,4,7,8 } ===> median is 4, range is 6
{ 2,3,5,7,8 } ===> median is 5, range is 6
{ 2,3,6,7,8 } ===> median is 6, range is 6
{ 2,3,7,7,8 } ===> median is 7, range is 6 
{ 2,3,7,8,8 } ===> median is 7, range is 6
{ 2,3,7,8,9 } ===> median is 7, range is 7,

that gives three instances where the median is greater than 5 and the range is still 6.  Therefore the answer is 30%.