Finding the Fourth Proportional to 81,078.72, 121,612.08 and 28,488.72

Step by Step Solution

1. Step 1: Write the proportion equation
   81,078.72 : 121,612.08 = 28,488.72 : x
2. Step 2: Convert to fraction form
   81,078.72/121,612.08 = 28,488.72/x
3. Step 3: Cross multiply
   81,078.72x = 121,612.08 × 28,488.72
4. Step 4: Simplify right side
   81,078.72x = 3,464,572,495.74
5. Step 5: Solve for x
   x = 3,464,572,495.74/81,078.72
6. Step 6: Final answer
   x = 42,730.97