Finding the Fourth Proportional to 2,187.72, 3,281.82 and 648.76

Step by Step Solution

1. Step 1: Write the proportion equation
   2,187.72 : 3,281.82 = 648.76 : x
2. Step 2: Convert to fraction form
   2,187.72/3,281.82 = 648.76/x
3. Step 3: Cross multiply
   2,187.72x = 3,281.82 × 648.76
4. Step 4: Simplify right side
   2,187.72x = 2,129,113.54
5. Step 5: Solve for x
   x = 2,129,113.54/2,187.72
6. Step 6: Final answer
   x = 973.21