Finding the Fourth Proportional to 6,630.48, 9,145.80 and 3,978.72

Step by Step Solution

1. Step 1: Write the proportion equation
   6,630.48 : 9,145.80 = 3,978.72 : x
2. Step 2: Convert to fraction form
   6,630.48/9,145.80 = 3,978.72/x
3. Step 3: Cross multiply
   6,630.48x = 9,145.80 × 3,978.72
4. Step 4: Simplify right side
   6,630.48x = 36,388,577.38
5. Step 5: Solve for x
   x = 36,388,577.38/6,630.48
6. Step 6: Final answer
   x = 5,488.08