Finding the Fourth Proportional to 8,978.73, 12,389.86 and 5,200.69

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.73 : 12,389.86 = 5,200.69 : x
2. Step 2: Convert to fraction form
   8,978.73/12,389.86 = 5,200.69/x
3. Step 3: Cross multiply
   8,978.73x = 12,389.86 × 5,200.69
4. Step 4: Simplify right side
   8,978.73x = 64,435,823.49
5. Step 5: Solve for x
   x = 64,435,823.49/8,978.73
6. Step 6: Final answer
   x = 7,176.49