Finding the Fourth Proportional to 143,061.60, 215,110.80 and 139,951.20

Step by Step Solution

1. Step 1: Write the proportion equation
   143,061.60 : 215,110.80 = 139,951.20 : x
2. Step 2: Convert to fraction form
   143,061.60/215,110.80 = 139,951.20/x
3. Step 3: Cross multiply
   143,061.60x = 215,110.80 × 139,951.20
4. Step 4: Simplify right side
   143,061.60x = 30,105,014,592.96
5. Step 5: Solve for x
   x = 30,105,014,592.96/143,061.60
6. Step 6: Final answer
   x = 210,433.93