Finding the Fourth Proportional to 12,618.72, 18,928.15 and 5,219.17

Step by Step Solution

1. Step 1: Write the proportion equation
   12,618.72 : 18,928.15 = 5,219.17 : x
2. Step 2: Convert to fraction form
   12,618.72/18,928.15 = 5,219.17/x
3. Step 3: Cross multiply
   12,618.72x = 18,928.15 × 5,219.17
4. Step 4: Simplify right side
   12,618.72x = 98,789,172.27
5. Step 5: Solve for x
   x = 98,789,172.27/12,618.72
6. Step 6: Final answer
   x = 7,828.78