Finding the Fourth Proportional to 31,567.42, 43,561.56 and 18,129.20

Step by Step Solution

1. Step 1: Write the proportion equation
   31,567.42 : 43,561.56 = 18,129.20 : x
2. Step 2: Convert to fraction form
   31,567.42/43,561.56 = 18,129.20/x
3. Step 3: Cross multiply
   31,567.42x = 43,561.56 × 18,129.20
4. Step 4: Simplify right side
   31,567.42x = 789,736,233.55
5. Step 5: Solve for x
   x = 789,736,233.55/31,567.42
6. Step 6: Final answer
   x = 25,017.45