Finding the Fourth Proportional to 1,162.56, 1,604.31 and 638.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.56 : 1,604.31 = 638.60 : x
2. Step 2: Convert to fraction form
   1,162.56/1,604.31 = 638.60/x
3. Step 3: Cross multiply
   1,162.56x = 1,604.31 × 638.60
4. Step 4: Simplify right side
   1,162.56x = 1,024,501.95
5. Step 5: Solve for x
   x = 1,024,501.95/1,162.56
6. Step 6: Final answer
   x = 881.24