Finding the Fourth Proportional to 2,547.09, 3,818.21 and 815.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,547.09 : 3,818.21 = 815.31 : x
2. Step 2: Convert to fraction form
   2,547.09/3,818.21 = 815.31/x
3. Step 3: Cross multiply
   2,547.09x = 3,818.21 × 815.31
4. Step 4: Simplify right side
   2,547.09x = 3,113,020.72
5. Step 5: Solve for x
   x = 3,113,020.72/2,547.09
6. Step 6: Final answer
   x = 1,222.19