Finding the Fourth Proportional to 1,225.89, 1,691.76 and 728.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,225.89 : 1,691.76 = 728.96 : x
2. Step 2: Convert to fraction form
   1,225.89/1,691.76 = 728.96/x
3. Step 3: Cross multiply
   1,225.89x = 1,691.76 × 728.96
4. Step 4: Simplify right side
   1,225.89x = 1,233,221.14
5. Step 5: Solve for x
   x = 1,233,221.14/1,225.89
6. Step 6: Final answer
   x = 1,005.98