Finding the Fourth Proportional to 6,978.62, 9,630.42 and 3,994.40

Step by Step Solution

1. Step 1: Write the proportion equation
   6,978.62 : 9,630.42 = 3,994.40 : x
2. Step 2: Convert to fraction form
   6,978.62/9,630.42 = 3,994.40/x
3. Step 3: Cross multiply
   6,978.62x = 9,630.42 × 3,994.40
4. Step 4: Simplify right side
   6,978.62x = 38,467,749.65
5. Step 5: Solve for x
   x = 38,467,749.65/6,978.62
6. Step 6: Final answer
   x = 5,512.23