Finding the Fourth Proportional to 8,978.66, 12,390.55 and 5,000.54

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.66 : 12,390.55 = 5,000.54 : x
2. Step 2: Convert to fraction form
   8,978.66/12,390.55 = 5,000.54/x
3. Step 3: Cross multiply
   8,978.66x = 12,390.55 × 5,000.54
4. Step 4: Simplify right side
   8,978.66x = 61,959,462.43
5. Step 5: Solve for x
   x = 61,959,462.43/8,978.66
6. Step 6: Final answer
   x = 6,900.75