Finding the Fourth Proportional to 139,150.61, 192,027.86 and 78,720.00

Step by Step Solution

1. Step 1: Write the proportion equation
   139,150.61 : 192,027.86 = 78,720.00 : x
2. Step 2: Convert to fraction form
   139,150.61/192,027.86 = 78,720.00/x
3. Step 3: Cross multiply
   139,150.61x = 192,027.86 × 78,720.00
4. Step 4: Simplify right side
   139,150.61x = 15,116,433,843.65
5. Step 5: Solve for x
   x = 15,116,433,843.65/139,150.61
6. Step 6: Final answer
   x = 108,633.62