Finding the Fourth Proportional to 1,162.72, 1,604.50 and 638.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.72 : 1,604.50 = 638.72 : x
2. Step 2: Convert to fraction form
   1,162.72/1,604.50 = 638.72/x
3. Step 3: Cross multiply
   1,162.72x = 1,604.50 × 638.72
4. Step 4: Simplify right side
   1,162.72x = 1,024,826.24
5. Step 5: Solve for x
   x = 1,024,826.24/1,162.72
6. Step 6: Final answer
   x = 881.40