Finding the Fourth Proportional to 139,345.32, 192,290.10 and 78,916.40

Step by Step Solution

1. Step 1: Write the proportion equation
   139,345.32 : 192,290.10 = 78,916.40 : x
2. Step 2: Convert to fraction form
   139,345.32/192,290.10 = 78,916.40/x
3. Step 3: Cross multiply
   139,345.32x = 192,290.10 × 78,916.40
4. Step 4: Simplify right side
   139,345.32x = 15,174,842,053.06
5. Step 5: Solve for x
   x = 15,174,842,053.06/139,345.32
6. Step 6: Final answer
   x = 108,900.98