Finding the Fourth Proportional to 21,879.98, 30,184.04 and 12,921.52

Step by Step Solution

1. Step 1: Write the proportion equation
   21,879.98 : 30,184.04 = 12,921.52 : x
2. Step 2: Convert to fraction form
   21,879.98/30,184.04 = 12,921.52/x
3. Step 3: Cross multiply
   21,879.98x = 30,184.04 × 12,921.52
4. Step 4: Simplify right side
   21,879.98x = 390,023,676.54
5. Step 5: Solve for x
   x = 390,023,676.54/21,879.98
6. Step 6: Final answer
   x = 17,825.60