Finding the Fourth Proportional to 2,048.72, 3,072.42 and 815.90

Step by Step Solution

1. Step 1: Write the proportion equation
   2,048.72 : 3,072.42 = 815.90 : x
2. Step 2: Convert to fraction form
   2,048.72/3,072.42 = 815.90/x
3. Step 3: Cross multiply
   2,048.72x = 3,072.42 × 815.90
4. Step 4: Simplify right side
   2,048.72x = 2,506,787.48
5. Step 5: Solve for x
   x = 2,506,787.48/2,048.72
6. Step 6: Final answer
   x = 1,223.59