Finding the Fourth Proportional to 13,385.27, 18,471.17 and 7,720.25

Step by Step Solution

1. Step 1: Write the proportion equation
   13,385.27 : 18,471.17 = 7,720.25 : x
2. Step 2: Convert to fraction form
   13,385.27/18,471.17 = 7,720.25/x
3. Step 3: Cross multiply
   13,385.27x = 18,471.17 × 7,720.25
4. Step 4: Simplify right side
   13,385.27x = 142,602,011.59
5. Step 5: Solve for x
   x = 142,602,011.59/13,385.27
6. Step 6: Final answer
   x = 10,653.66