Finding the Fourth Proportional to 10,078.74, 13,909.57 and 5,603.40

Step by Step Solution

1. Step 1: Write the proportion equation
   10,078.74 : 13,909.57 = 5,603.40 : x
2. Step 2: Convert to fraction form
   10,078.74/13,909.57 = 5,603.40/x
3. Step 3: Cross multiply
   10,078.74x = 13,909.57 × 5,603.40
4. Step 4: Simplify right side
   10,078.74x = 77,940,884.54
5. Step 5: Solve for x
   x = 77,940,884.54/10,078.74
6. Step 6: Final answer
   x = 7,733.20