Finding the Fourth Proportional to 13,138.25, 18,134.24 and 8,420.00

Step by Step Solution

1. Step 1: Write the proportion equation
   13,138.25 : 18,134.24 = 8,420.00 : x
2. Step 2: Convert to fraction form
   13,138.25/18,134.24 = 8,420.00/x
3. Step 3: Cross multiply
   13,138.25x = 18,134.24 × 8,420.00
4. Step 4: Simplify right side
   13,138.25x = 152,690,168.03
5. Step 5: Solve for x
   x = 152,690,168.03/13,138.25
6. Step 6: Final answer
   x = 11,621.81