Finding the Fourth Proportional to 21,948.48, 30,289.37 and 12,992.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,948.48 : 30,289.37 = 12,992.72 : x
2. Step 2: Convert to fraction form
   21,948.48/30,289.37 = 12,992.72/x
3. Step 3: Cross multiply
   21,948.48x = 30,289.37 × 12,992.72
4. Step 4: Simplify right side
   21,948.48x = 393,541,086.98
5. Step 5: Solve for x
   x = 393,541,086.98/21,948.48
6. Step 6: Final answer
   x = 17,930.22