Finding the Fourth Proportional to 28,278.72, 42,418.69 and 8,557.25

Step by Step Solution

1. Step 1: Write the proportion equation
   28,278.72 : 42,418.69 = 8,557.25 : x
2. Step 2: Convert to fraction form
   28,278.72/42,418.69 = 8,557.25/x
3. Step 3: Cross multiply
   28,278.72x = 42,418.69 × 8,557.25
4. Step 4: Simplify right side
   28,278.72x = 362,987,101.52
5. Step 5: Solve for x
   x = 362,987,101.52/28,278.72
6. Step 6: Final answer
   x = 12,836.05