Finding the Fourth Proportional to 20,869.02, 31,302.72 and 8,385.30

Step by Step Solution

1. Step 1: Write the proportion equation
   20,869.02 : 31,302.72 = 8,385.30 : x
2. Step 2: Convert to fraction form
   20,869.02/31,302.72 = 8,385.30/x
3. Step 3: Cross multiply
   20,869.02x = 31,302.72 × 8,385.30
4. Step 4: Simplify right side
   20,869.02x = 262,482,698.02
5. Step 5: Solve for x
   x = 262,482,698.02/20,869.02
6. Step 6: Final answer
   x = 12,577.62