Finding the Fourth Proportional to 18,978.96, 28,470.12 and 4,938.96

Step by Step Solution

1. Step 1: Write the proportion equation
   18,978.96 : 28,470.12 = 4,938.96 : x
2. Step 2: Convert to fraction form
   18,978.96/28,470.12 = 4,938.96/x
3. Step 3: Cross multiply
   18,978.96x = 28,470.12 × 4,938.96
4. Step 4: Simplify right side
   18,978.96x = 140,612,783.88
5. Step 5: Solve for x
   x = 140,612,783.88/18,978.96
6. Step 6: Final answer
   x = 7,408.88