Finding the Fourth Proportional to 3,978.72, 5,489.28 and 2,299.68

Step by Step Solution

1. Step 1: Write the proportion equation
   3,978.72 : 5,489.28 = 2,299.68 : x
2. Step 2: Convert to fraction form
   3,978.72/5,489.28 = 2,299.68/x
3. Step 3: Cross multiply
   3,978.72x = 5,489.28 × 2,299.68
4. Step 4: Simplify right side
   3,978.72x = 12,623,587.43
5. Step 5: Solve for x
   x = 12,623,587.43/3,978.72
6. Step 6: Final answer
   x = 3,172.78