Finding the Fourth Proportional to 438,870.72, 658,238.85 and 139,312.47

Step by Step Solution

1. Step 1: Write the proportion equation
   438,870.72 : 658,238.85 = 139,312.47 : x
2. Step 2: Convert to fraction form
   438,870.72/658,238.85 = 139,312.47/x
3. Step 3: Cross multiply
   438,870.72x = 658,238.85 × 139,312.47
4. Step 4: Simplify right side
   438,870.72x = 91,700,880,043.46
5. Step 5: Solve for x
   x = 91,700,880,043.46/438,870.72
6. Step 6: Final answer
   x = 208,947.36