Finding the Fourth Proportional to 123,609.28, 170,518 and 78,210.72

Step by Step Solution

1. Step 1: Write the proportion equation
   123,609.28 : 170,518 = 78,210.72 : x
2. Step 2: Convert to fraction form
   123,609.28/170,518 = 78,210.72/x
3. Step 3: Cross multiply
   123,609.28x = 170,518 × 78,210.72
4. Step 4: Simplify right side
   123,609.28x = 13,336,335,552.96
5. Step 5: Solve for x
   x = 13,336,335,552.96/123,609.28
6. Step 6: Final answer
   x = 107,891.05