Finding the Fourth Proportional to 78,478.34, 116,978.21 and 72,179.78

Step by Step Solution

1. Step 1: Write the proportion equation
   78,478.34 : 116,978.21 = 72,179.78 : x
2. Step 2: Convert to fraction form
   78,478.34/116,978.21 = 72,179.78/x
3. Step 3: Cross multiply
   78,478.34x = 116,978.21 × 72,179.78
4. Step 4: Simplify right side
   78,478.34x = 8,443,460,787.48
5. Step 5: Solve for x
   x = 8,443,460,787.48/78,478.34
6. Step 6: Final answer
   x = 107,589.70