Finding the Fourth Proportional to 139,061.07, 191,903.11 and 78,643.57

Step by Step Solution

1. Step 1: Write the proportion equation
   139,061.07 : 191,903.11 = 78,643.57 : x
2. Step 2: Convert to fraction form
   139,061.07/191,903.11 = 78,643.57/x
3. Step 3: Cross multiply
   139,061.07x = 191,903.11 × 78,643.57
4. Step 4: Simplify right side
   139,061.07x = 15,091,945,664.50
5. Step 5: Solve for x
   x = 15,091,945,664.50/139,061.07
6. Step 6: Final answer
   x = 108,527.47