Finding the Fourth Proportional to 8,705.20, 12,012.84 and 4,979.12

Step by Step Solution

1. Step 1: Write the proportion equation
   8,705.20 : 12,012.84 = 4,979.12 : x
2. Step 2: Convert to fraction form
   8,705.20/12,012.84 = 4,979.12/x
3. Step 3: Cross multiply
   8,705.20x = 12,012.84 × 4,979.12
4. Step 4: Simplify right side
   8,705.20x = 59,813,371.90
5. Step 5: Solve for x
   x = 59,813,371.90/8,705.20
6. Step 6: Final answer
   x = 6,870.99