Finding the Fourth Proportional to 21,141.72, 31,709.84 and 7,992.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,141.72 : 31,709.84 = 7,992.38 : x
2. Step 2: Convert to fraction form
   21,141.72/31,709.84 = 7,992.38/x
3. Step 3: Cross multiply
   21,141.72x = 31,709.84 × 7,992.38
4. Step 4: Simplify right side
   21,141.72x = 253,436,892.51
5. Step 5: Solve for x
   x = 253,436,892.51/21,141.72
6. Step 6: Final answer
   x = 11,987.52