Finding the Fourth Proportional to 139,059.57, 191,901.05 and 78,642.07

Step by Step Solution

1. Step 1: Write the proportion equation
   139,059.57 : 191,901.05 = 78,642.07 : x
2. Step 2: Convert to fraction form
   139,059.57/191,901.05 = 78,642.07/x
3. Step 3: Cross multiply
   139,059.57x = 191,901.05 × 78,642.07
4. Step 4: Simplify right side
   139,059.57x = 15,091,495,413.96
5. Step 5: Solve for x
   x = 15,091,495,413.96/139,059.57
6. Step 6: Final answer
   x = 108,525.40