Finding the Fourth Proportional to 8,586.84, 12,879.72 and 3,320.80

Step by Step Solution

1. Step 1: Write the proportion equation
   8,586.84 : 12,879.72 = 3,320.80 : x
2. Step 2: Convert to fraction form
   8,586.84/12,879.72 = 3,320.80/x
3. Step 3: Cross multiply
   8,586.84x = 12,879.72 × 3,320.80
4. Step 4: Simplify right side
   8,586.84x = 42,770,974.18
5. Step 5: Solve for x
   x = 42,770,974.18/8,586.84
6. Step 6: Final answer
   x = 4,980.99