Finding the Fourth Proportional to 20,172.78, 30,240.72 and 8,486.82

Step by Step Solution

1. Step 1: Write the proportion equation
   20,172.78 : 30,240.72 = 8,486.82 : x
2. Step 2: Convert to fraction form
   20,172.78/30,240.72 = 8,486.82/x
3. Step 3: Cross multiply
   20,172.78x = 30,240.72 × 8,486.82
4. Step 4: Simplify right side
   20,172.78x = 256,647,547.31
5. Step 5: Solve for x
   x = 256,647,547.31/20,172.78
6. Step 6: Final answer
   x = 12,722.47