Finding the Fourth Proportional to 21,144.86, 31,717.81 and 7,105.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,144.86 : 31,717.81 = 7,105.09 : x
2. Step 2: Convert to fraction form
   21,144.86/31,717.81 = 7,105.09/x
3. Step 3: Cross multiply
   21,144.86x = 31,717.81 × 7,105.09
4. Step 4: Simplify right side
   21,144.86x = 225,357,859.13
5. Step 5: Solve for x
   x = 225,357,859.13/21,144.86
6. Step 6: Final answer
   x = 10,657.81