Finding the Fourth Proportional to 1,168.50, 1,612.53 and 644.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.50 : 1,612.53 = 644.55 : x
2. Step 2: Convert to fraction form
   1,168.50/1,612.53 = 644.55/x
3. Step 3: Cross multiply
   1,168.50x = 1,612.53 × 644.55
4. Step 4: Simplify right side
   1,168.50x = 1,039,356.21
5. Step 5: Solve for x
   x = 1,039,356.21/1,168.50
6. Step 6: Final answer
   x = 889.48