Finding the Fourth Proportional to 21,145.06, 31,718.11 and 7,105.29

Step by Step Solution

1. Step 1: Write the proportion equation
   21,145.06 : 31,718.11 = 7,105.29 : x
2. Step 2: Convert to fraction form
   21,145.06/31,718.11 = 7,105.29/x
3. Step 3: Cross multiply
   21,145.06x = 31,718.11 × 7,105.29
4. Step 4: Simplify right side
   21,145.06x = 225,366,404.85
5. Step 5: Solve for x
   x = 225,366,404.85/21,145.06
6. Step 6: Final answer
   x = 10,658.11