Finding the Fourth Proportional to 12,087.30, 18,128.82 and 3,320.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,087.30 : 18,128.82 = 3,320.10 : x
2. Step 2: Convert to fraction form
   12,087.30/18,128.82 = 3,320.10/x
3. Step 3: Cross multiply
   12,087.30x = 18,128.82 × 3,320.10
4. Step 4: Simplify right side
   12,087.30x = 60,189,495.28
5. Step 5: Solve for x
   x = 60,189,495.28/12,087.30
6. Step 6: Final answer
   x = 4,979.56