Finding the Fourth Proportional to 13,509.15, 18,642.61 and 7,540.81

Step by Step Solution

1. Step 1: Write the proportion equation
   13,509.15 : 18,642.61 = 7,540.81 : x
2. Step 2: Convert to fraction form
   13,509.15/18,642.61 = 7,540.81/x
3. Step 3: Cross multiply
   13,509.15x = 18,642.61 × 7,540.81
4. Step 4: Simplify right side
   13,509.15x = 140,580,405.18
5. Step 5: Solve for x
   x = 140,580,405.18/13,509.15
6. Step 6: Final answer
   x = 10,406.31