Finding the Fourth Proportional to 13,081.15, 18,051.90 and 7,112.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,081.15 : 18,051.90 = 7,112.80 : x
2. Step 2: Convert to fraction form
   13,081.15/18,051.90 = 7,112.80/x
3. Step 3: Cross multiply
   13,081.15x = 18,051.90 × 7,112.80
4. Step 4: Simplify right side
   13,081.15x = 128,399,554.32
5. Step 5: Solve for x
   x = 128,399,554.32/13,081.15
6. Step 6: Final answer
   x = 9,815.62