Finding the Fourth Proportional to 8,978.12, 12,390.30 and 4,999.14

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.12 : 12,390.30 = 4,999.14 : x
2. Step 2: Convert to fraction form
   8,978.12/12,390.30 = 4,999.14/x
3. Step 3: Cross multiply
   8,978.12x = 12,390.30 × 4,999.14
4. Step 4: Simplify right side
   8,978.12x = 61,940,844.34
5. Step 5: Solve for x
   x = 61,940,844.34/8,978.12
6. Step 6: Final answer
   x = 6,899.09