Finding the Fourth Proportional to 6,978.72, 9,615.12 and 4,490.40

Step by Step Solution

1. Step 1: Write the proportion equation
   6,978.72 : 9,615.12 = 4,490.40 : x
2. Step 2: Convert to fraction form
   6,978.72/9,615.12 = 4,490.40/x
3. Step 3: Cross multiply
   6,978.72x = 9,615.12 × 4,490.40
4. Step 4: Simplify right side
   6,978.72x = 43,175,734.85
5. Step 5: Solve for x
   x = 43,175,734.85/6,978.72
6. Step 6: Final answer
   x = 6,186.77