Finding the Fourth Proportional to 1,168.87, 1,613.06 and 644.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.87 : 1,613.06 = 644.89 : x
2. Step 2: Convert to fraction form
   1,168.87/1,613.06 = 644.89/x
3. Step 3: Cross multiply
   1,168.87x = 1,613.06 × 644.89
4. Step 4: Simplify right side
   1,168.87x = 1,040,234.97
5. Step 5: Solve for x
   x = 1,040,234.97/1,168.87
6. Step 6: Final answer
   x = 889.95