Finding the Fourth Proportional to 8,978.08, 12,389.40 and 4,999.12

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.08 : 12,389.40 = 4,999.12 : x
2. Step 2: Convert to fraction form
   8,978.08/12,389.40 = 4,999.12/x
3. Step 3: Cross multiply
   8,978.08x = 12,389.40 × 4,999.12
4. Step 4: Simplify right side
   8,978.08x = 61,936,097.33
5. Step 5: Solve for x
   x = 61,936,097.33/8,978.08
6. Step 6: Final answer
   x = 6,898.59