Finding the Fourth Proportional to 6,978.81, 9,629.96 and 3,994.47

Step by Step Solution

1. Step 1: Write the proportion equation
   6,978.81 : 9,629.96 = 3,994.47 : x
2. Step 2: Convert to fraction form
   6,978.81/9,629.96 = 3,994.47/x
3. Step 3: Cross multiply
   6,978.81x = 9,629.96 × 3,994.47
4. Step 4: Simplify right side
   6,978.81x = 38,466,566.35
5. Step 5: Solve for x
   x = 38,466,566.35/6,978.81
6. Step 6: Final answer
   x = 5,511.91