Finding the Fourth Proportional to 1,789.49, 2,685.15 and 815.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,789.49 : 2,685.15 = 815.47 : x
2. Step 2: Convert to fraction form
   1,789.49/2,685.15 = 815.47/x
3. Step 3: Cross multiply
   1,789.49x = 2,685.15 × 815.47
4. Step 4: Simplify right side
   1,789.49x = 2,189,641.77
5. Step 5: Solve for x
   x = 2,189,641.77/1,789.49
6. Step 6: Final answer
   x = 1,223.61