Finding the Fourth Proportional to 10,419.18, 14,378.49 and 5,639.13

Step by Step Solution

1. Step 1: Write the proportion equation
   10,419.18 : 14,378.49 = 5,639.13 : x
2. Step 2: Convert to fraction form
   10,419.18/14,378.49 = 5,639.13/x
3. Step 3: Cross multiply
   10,419.18x = 14,378.49 × 5,639.13
4. Step 4: Simplify right side
   10,419.18x = 81,082,107.20
5. Step 5: Solve for x
   x = 81,082,107.20/10,419.18
6. Step 6: Final answer
   x = 7,782.00