Finding the Fourth Proportional to 20,111.70, 30,171.15 and 8,426.10

Step by Step Solution

1. Step 1: Write the proportion equation
   20,111.70 : 30,171.15 = 8,426.10 : x
2. Step 2: Convert to fraction form
   20,111.70/30,171.15 = 8,426.10/x
3. Step 3: Cross multiply
   20,111.70x = 30,171.15 × 8,426.10
4. Step 4: Simplify right side
   20,111.70x = 254,225,127.02
5. Step 5: Solve for x
   x = 254,225,127.02/20,111.70
6. Step 6: Final answer
   x = 12,640.66