Finding the Fourth Proportional to 8,978.49, 12,391.11 and 5,443.65

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.49 : 12,391.11 = 5,443.65 : x
2. Step 2: Convert to fraction form
   8,978.49/12,391.11 = 5,443.65/x
3. Step 3: Cross multiply
   8,978.49x = 12,391.11 × 5,443.65
4. Step 4: Simplify right side
   8,978.49x = 67,452,865.95
5. Step 5: Solve for x
   x = 67,452,865.95/8,978.49
6. Step 6: Final answer
   x = 7,512.72