Finding the Fourth Proportional to 2,663.36, 3,993.72 and 814.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,663.36 : 3,993.72 = 814.12 : x
2. Step 2: Convert to fraction form
   2,663.36/3,993.72 = 814.12/x
3. Step 3: Cross multiply
   2,663.36x = 3,993.72 × 814.12
4. Step 4: Simplify right side
   2,663.36x = 3,251,367.33
5. Step 5: Solve for x
   x = 3,251,367.33/2,663.36
6. Step 6: Final answer
   x = 1,220.78