Finding the Fourth Proportional to 28,139.47, 42,178.83 and 18,285.82

Step by Step Solution

1. Step 1: Write the proportion equation
   28,139.47 : 42,178.83 = 18,285.82 : x
2. Step 2: Convert to fraction form
   28,139.47/42,178.83 = 18,285.82/x
3. Step 3: Cross multiply
   28,139.47x = 42,178.83 × 18,285.82
4. Step 4: Simplify right side
   28,139.47x = 771,274,493.19
5. Step 5: Solve for x
   x = 771,274,493.19/28,139.47
6. Step 6: Final answer
   x = 27,408.99