Finding the Fourth Proportional to 1,162.75, 1,604.60 and 638.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.75 : 1,604.60 = 638.79 : x
2. Step 2: Convert to fraction form
   1,162.75/1,604.60 = 638.79/x
3. Step 3: Cross multiply
   1,162.75x = 1,604.60 × 638.79
4. Step 4: Simplify right side
   1,162.75x = 1,025,002.43
5. Step 5: Solve for x
   x = 1,025,002.43/1,162.75
6. Step 6: Final answer
   x = 881.53