Finding the Fourth Proportional to 102,689.98, 141,510.28 and 78,518.31

Step by Step Solution

1. Step 1: Write the proportion equation
   102,689.98 : 141,510.28 = 78,518.31 : x
2. Step 2: Convert to fraction form
   102,689.98/141,510.28 = 78,518.31/x
3. Step 3: Cross multiply
   102,689.98x = 141,510.28 × 78,518.31
4. Step 4: Simplify right side
   102,689.98x = 11,111,148,033.23
5. Step 5: Solve for x
   x = 11,111,148,033.23/102,689.98
6. Step 6: Final answer
   x = 108,200.90