Finding the Fourth Proportional to 8,918.72, 12,308.53 and 4,940.21

Step by Step Solution

1. Step 1: Write the proportion equation
   8,918.72 : 12,308.53 = 4,940.21 : x
2. Step 2: Convert to fraction form
   8,918.72/12,308.53 = 4,940.21/x
3. Step 3: Cross multiply
   8,918.72x = 12,308.53 × 4,940.21
4. Step 4: Simplify right side
   8,918.72x = 60,806,695.33
5. Step 5: Solve for x
   x = 60,806,695.33/8,918.72
6. Step 6: Final answer
   x = 6,817.87