Finding the Fourth Proportional to 1,458.72, 2,188.18 and 485.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,458.72 : 2,188.18 = 485.50 : x
2. Step 2: Convert to fraction form
   1,458.72/2,188.18 = 485.50/x
3. Step 3: Cross multiply
   1,458.72x = 2,188.18 × 485.50
4. Step 4: Simplify right side
   1,458.72x = 1,062,361.39
5. Step 5: Solve for x
   x = 1,062,361.39/1,458.72
6. Step 6: Final answer
   x = 728.28