Finding the Fourth Proportional to 21,068.24, 31,607.06 and 7,920.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,068.24 : 31,607.06 = 7,920.72 : x
2. Step 2: Convert to fraction form
   21,068.24/31,607.06 = 7,920.72/x
3. Step 3: Cross multiply
   21,068.24x = 31,607.06 × 7,920.72
4. Step 4: Simplify right side
   21,068.24x = 250,350,632.68
5. Step 5: Solve for x
   x = 250,350,632.68/21,068.24
6. Step 6: Final answer
   x = 11,882.85