Finding the Fourth Proportional to 1,162.88, 1,604.78 and 638.93

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.88 : 1,604.78 = 638.93 : x
2. Step 2: Convert to fraction form
   1,162.88/1,604.78 = 638.93/x
3. Step 3: Cross multiply
   1,162.88x = 1,604.78 × 638.93
4. Step 4: Simplify right side
   1,162.88x = 1,025,330.87
5. Step 5: Solve for x
   x = 1,025,330.87/1,162.88
6. Step 6: Final answer
   x = 881.72