Finding the Fourth Proportional to 12,455.69, 17,187.45 and 7,419.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,455.69 : 17,187.45 = 7,419.20 : x
2. Step 2: Convert to fraction form
   12,455.69/17,187.45 = 7,419.20/x
3. Step 3: Cross multiply
   12,455.69x = 17,187.45 × 7,419.20
4. Step 4: Simplify right side
   12,455.69x = 127,517,043.10
5. Step 5: Solve for x
   x = 127,517,043.10/12,455.69
6. Step 6: Final answer
   x = 10,237.66