Finding the Fourth Proportional to 28,142.37, 42,219 and 8,419.23

Step by Step Solution

1. Step 1: Write the proportion equation
   28,142.37 : 42,219 = 8,419.23 : x
2. Step 2: Convert to fraction form
   28,142.37/42,219 = 8,419.23/x
3. Step 3: Cross multiply
   28,142.37x = 42,219 × 8,419.23
4. Step 4: Simplify right side
   28,142.37x = 355,451,471.37
5. Step 5: Solve for x
   x = 355,451,471.37/28,142.37
6. Step 6: Final answer
   x = 12,630.47