Finding the Fourth Proportional to 13,108.72, 18,090.54 and 7,520.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,108.72 : 18,090.54 = 7,520.80 : x
2. Step 2: Convert to fraction form
   13,108.72/18,090.54 = 7,520.80/x
3. Step 3: Cross multiply
   13,108.72x = 18,090.54 × 7,520.80
4. Step 4: Simplify right side
   13,108.72x = 136,055,333.23
5. Step 5: Solve for x
   x = 136,055,333.23/13,108.72
6. Step 6: Final answer
   x = 10,378.99