Finding the Fourth Proportional to 21,145.87, 31,718.71 and 5,351.05

Step by Step Solution

1. Step 1: Write the proportion equation
   21,145.87 : 31,718.71 = 5,351.05 : x
2. Step 2: Convert to fraction form
   21,145.87/31,718.71 = 5,351.05/x
3. Step 3: Cross multiply
   21,145.87x = 31,718.71 × 5,351.05
4. Step 4: Simplify right side
   21,145.87x = 169,728,403.15
5. Step 5: Solve for x
   x = 169,728,403.15/21,145.87
6. Step 6: Final answer
   x = 8,026.55