Finding the Fourth Proportional to 438,561.72, 657,837.18 and 139,041.72

Step by Step Solution

1. Step 1: Write the proportion equation
   438,561.72 : 657,837.18 = 139,041.72 : x
2. Step 2: Convert to fraction form
   438,561.72/657,837.18 = 139,041.72/x
3. Step 3: Cross multiply
   438,561.72x = 657,837.18 × 139,041.72
4. Step 4: Simplify right side
   438,561.72x = 91,466,812,987.15
5. Step 5: Solve for x
   x = 91,466,812,987.15/438,561.72
6. Step 6: Final answer
   x = 208,560.87