Finding the Fourth Proportional to 1,083.68, 1,496.20 and 641.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,083.68 : 1,496.20 = 641.72 : x
2. Step 2: Convert to fraction form
   1,083.68/1,496.20 = 641.72/x
3. Step 3: Cross multiply
   1,083.68x = 1,496.20 × 641.72
4. Step 4: Simplify right side
   1,083.68x = 960,143.00
5. Step 5: Solve for x
   x = 960,143.00/1,083.68
6. Step 6: Final answer
   x = 886.00