Finding the Fourth Proportional to 2,208.72, 3,313.50 and 648.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,208.72 : 3,313.50 = 648.72 : x
2. Step 2: Convert to fraction form
   2,208.72/3,313.50 = 648.72/x
3. Step 3: Cross multiply
   2,208.72x = 3,313.50 × 648.72
4. Step 4: Simplify right side
   2,208.72x = 2,149,533.72
5. Step 5: Solve for x
   x = 2,149,533.72/2,208.72
6. Step 6: Final answer
   x = 973.20