Finding the Fourth Proportional to 1,102.57, 1,521.61 and 728.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,102.57 : 1,521.61 = 728.89 : x
2. Step 2: Convert to fraction form
   1,102.57/1,521.61 = 728.89/x
3. Step 3: Cross multiply
   1,102.57x = 1,521.61 × 728.89
4. Step 4: Simplify right side
   1,102.57x = 1,109,080.69
5. Step 5: Solve for x
   x = 1,109,080.69/1,102.57
6. Step 6: Final answer
   x = 1,005.91