Finding the Fourth Proportional to 31,561.60, 43,557.12 and 18,137.20

Step by Step Solution

1. Step 1: Write the proportion equation
   31,561.60 : 43,557.12 = 18,137.20 : x
2. Step 2: Convert to fraction form
   31,561.60/43,557.12 = 18,137.20/x
3. Step 3: Cross multiply
   31,561.60x = 43,557.12 × 18,137.20
4. Step 4: Simplify right side
   31,561.60x = 790,004,196.86
5. Step 5: Solve for x
   x = 790,004,196.86/31,561.60
6. Step 6: Final answer
   x = 25,030.55