Finding the Fourth Proportional to 85,680.72, 128,579.22 and 30,276.72

Step by Step Solution

1. Step 1: Write the proportion equation
   85,680.72 : 128,579.22 = 30,276.72 : x
2. Step 2: Convert to fraction form
   85,680.72/128,579.22 = 30,276.72/x
3. Step 3: Cross multiply
   85,680.72x = 128,579.22 × 30,276.72
4. Step 4: Simplify right side
   85,680.72x = 3,892,957,041.76
5. Step 5: Solve for x
   x = 3,892,957,041.76/85,680.72
6. Step 6: Final answer
   x = 45,435.62