Finding the Fourth Proportional to 13,561.76, 20,354.69 and 11,354.31

Step by Step Solution

1. Step 1: Write the proportion equation
   13,561.76 : 20,354.69 = 11,354.31 : x
2. Step 2: Convert to fraction form
   13,561.76/20,354.69 = 11,354.31/x
3. Step 3: Cross multiply
   13,561.76x = 20,354.69 × 11,354.31
4. Step 4: Simplify right side
   13,561.76x = 231,113,488.60
5. Step 5: Solve for x
   x = 231,113,488.60/13,561.76
6. Step 6: Final answer
   x = 17,041.55