Finding the Fourth Proportional to 6,978.78, 9,630.36 and 3,994.38

Step by Step Solution

1. Step 1: Write the proportion equation
   6,978.78 : 9,630.36 = 3,994.38 : x
2. Step 2: Convert to fraction form
   6,978.78/9,630.36 = 3,994.38/x
3. Step 3: Cross multiply
   6,978.78x = 9,630.36 × 3,994.38
4. Step 4: Simplify right side
   6,978.78x = 38,467,317.38
5. Step 5: Solve for x
   x = 38,467,317.38/6,978.78
6. Step 6: Final answer
   x = 5,512.04