Answer:
x = 15
The median is the middle number, however, in this case there are two:
25 and x
The formula is:
23 + x/2 = 30.5
Subtract 23 from both sides:
23 + x - 23 = 30.5 - 23
Simplify:
x/2 = 7.5
Multiply both sides by 2:
2x/2 = 7.5 ⋅ 2
Therefore:
x = 15