Finding the Fourth Proportional to 39,485.83, 54,490.47 and 21,580.83

Step by Step Solution

1. Step 1: Write the proportion equation
   39,485.83 : 54,490.47 = 21,580.83 : x
2. Step 2: Convert to fraction form
   39,485.83/54,490.47 = 21,580.83/x
3. Step 3: Cross multiply
   39,485.83x = 54,490.47 × 21,580.83
4. Step 4: Simplify right side
   39,485.83x = 1,175,949,610.15
5. Step 5: Solve for x
   x = 1,175,949,610.15/39,485.83
6. Step 6: Final answer
   x = 29,781.56