Finding the Fourth Proportional to 8,978.31, 12,363.32 and 8,779.17

Step by Step Solution

1. Step 1: Write the proportion equation
   8,978.31 : 12,363.32 = 8,779.17 : x
2. Step 2: Convert to fraction form
   8,978.31/12,363.32 = 8,779.17/x
3. Step 3: Cross multiply
   8,978.31x = 12,363.32 × 8,779.17
4. Step 4: Simplify right side
   8,978.31x = 108,539,626.23
5. Step 5: Solve for x
   x = 108,539,626.23/8,978.31
6. Step 6: Final answer
   x = 12,089.10