Finding the Fourth Proportional to 8,705.19, 12,011.90 and 4,978.47

Step by Step Solution

1. Step 1: Write the proportion equation
   8,705.19 : 12,011.90 = 4,978.47 : x
2. Step 2: Convert to fraction form
   8,705.19/12,011.90 = 4,978.47/x
3. Step 3: Cross multiply
   8,705.19x = 12,011.90 × 4,978.47
4. Step 4: Simplify right side
   8,705.19x = 59,800,858.90
5. Step 5: Solve for x
   x = 59,800,858.90/8,705.19
6. Step 6: Final answer
   x = 6,869.56