Finding the Fourth Proportional to 2,663.88, 3,996.22 and 815.25

Step by Step Solution

1. Step 1: Write the proportion equation
   2,663.88 : 3,996.22 = 815.25 : x
2. Step 2: Convert to fraction form
   2,663.88/3,996.22 = 815.25/x
3. Step 3: Cross multiply
   2,663.88x = 3,996.22 × 815.25
4. Step 4: Simplify right side
   2,663.88x = 3,257,918.36
5. Step 5: Solve for x
   x = 3,257,918.36/2,663.88
6. Step 6: Final answer
   x = 1,223.00