Finding the Fourth Proportional to 1,076.91, 1,616.81 and 638.97

Step by Step Solution

1. Step 1: Write the proportion equation
   1,076.91 : 1,616.81 = 638.97 : x
2. Step 2: Convert to fraction form
   1,076.91/1,616.81 = 638.97/x
3. Step 3: Cross multiply
   1,076.91x = 1,616.81 × 638.97
4. Step 4: Simplify right side
   1,076.91x = 1,033,089.89
5. Step 5: Solve for x
   x = 1,033,089.89/1,076.91
6. Step 6: Final answer
   x = 959.31