Finding the Fourth Proportional to 1,168.76, 1,612.76 and 644.69

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.76 : 1,612.76 = 644.69 : x
2. Step 2: Convert to fraction form
   1,168.76/1,612.76 = 644.69/x
3. Step 3: Cross multiply
   1,168.76x = 1,612.76 × 644.69
4. Step 4: Simplify right side
   1,168.76x = 1,039,718.96
5. Step 5: Solve for x
   x = 1,039,718.96/1,168.76
6. Step 6: Final answer
   x = 889.60