Finding the Fourth Proportional to 1,143.27, 1,715.31 and 485.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,143.27 : 1,715.31 = 485.31 : x
2. Step 2: Convert to fraction form
   1,143.27/1,715.31 = 485.31/x
3. Step 3: Cross multiply
   1,143.27x = 1,715.31 × 485.31
4. Step 4: Simplify right side
   1,143.27x = 832,457.10
5. Step 5: Solve for x
   x = 832,457.10/1,143.27
6. Step 6: Final answer
   x = 728.14