Finding the Fourth Proportional to 20,271.72, 30,410.78 and 8,585

Step by Step Solution

1. Step 1: Write the proportion equation
   20,271.72 : 30,410.78 = 8,585 : x
2. Step 2: Convert to fraction form
   20,271.72/30,410.78 = 8,585/x
3. Step 3: Cross multiply
   20,271.72x = 30,410.78 × 8,585
4. Step 4: Simplify right side
   20,271.72x = 261,076,546.30
5. Step 5: Solve for x
   x = 261,076,546.30/20,271.72
6. Step 6: Final answer
   x = 12,878.86