Finding the Fourth Proportional to 18,978.77, 28,463.15 and 5,648.18

Step by Step Solution

1. Step 1: Write the proportion equation
   18,978.77 : 28,463.15 = 5,648.18 : x
2. Step 2: Convert to fraction form
   18,978.77/28,463.15 = 5,648.18/x
3. Step 3: Cross multiply
   18,978.77x = 28,463.15 × 5,648.18
4. Step 4: Simplify right side
   18,978.77x = 160,764,824.01
5. Step 5: Solve for x
   x = 160,764,824.01/18,978.77
6. Step 6: Final answer
   x = 8,470.77