Finding the Fourth Proportional to 103,688.10, 155,696.18 and 78,756.30

Step by Step Solution

1. Step 1: Write the proportion equation
   103,688.10 : 155,696.18 = 78,756.30 : x
2. Step 2: Convert to fraction form
   103,688.10/155,696.18 = 78,756.30/x
3. Step 3: Cross multiply
   103,688.10x = 155,696.18 × 78,756.30
4. Step 4: Simplify right side
   103,688.10x = 12,262,055,060.93
5. Step 5: Solve for x
   x = 12,262,055,060.93/103,688.10
6. Step 6: Final answer
   x = 118,259.04