Finding the Fourth Proportional to 1,013.72, 1,520.17 and 397.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,013.72 : 1,520.17 = 397.10 : x
2. Step 2: Convert to fraction form
   1,013.72/1,520.17 = 397.10/x
3. Step 3: Cross multiply
   1,013.72x = 1,520.17 × 397.10
4. Step 4: Simplify right side
   1,013.72x = 603,662.31
5. Step 5: Solve for x
   x = 603,662.31/1,013.72
6. Step 6: Final answer
   x = 595.50