Finding the Fourth Proportional to 1,513.10, 2,270.31 and 820.27

Step by Step Solution

1. Step 1: Write the proportion equation
   1,513.10 : 2,270.31 = 820.27 : x
2. Step 2: Convert to fraction form
   1,513.10/2,270.31 = 820.27/x
3. Step 3: Cross multiply
   1,513.10x = 2,270.31 × 820.27
4. Step 4: Simplify right side
   1,513.10x = 1,862,259.46
5. Step 5: Solve for x
   x = 1,862,259.46/1,513.10
6. Step 6: Final answer
   x = 1,230.76