Finding the Fourth Proportional to 13,420.72, 20,131.54 and 3,561.00

Step by Step Solution

1. Step 1: Write the proportion equation
   13,420.72 : 20,131.54 = 3,561.00 : x
2. Step 2: Convert to fraction form
   13,420.72/20,131.54 = 3,561.00/x
3. Step 3: Cross multiply
   13,420.72x = 20,131.54 × 3,561.00
4. Step 4: Simplify right side
   13,420.72x = 71,688,329.54
5. Step 5: Solve for x
   x = 71,688,329.54/13,420.72
6. Step 6: Final answer
   x = 5,341.62