Finding the Fourth Proportional to 1,168.86, 1,613.01 and 644.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,168.86 : 1,613.01 = 644.88 : x
2. Step 2: Convert to fraction form
   1,168.86/1,613.01 = 644.88/x
3. Step 3: Cross multiply
   1,168.86x = 1,613.01 × 644.88
4. Step 4: Simplify right side
   1,168.86x = 1,040,197.89
5. Step 5: Solve for x
   x = 1,040,197.89/1,168.86
6. Step 6: Final answer
   x = 889.93