Finding the Fourth Proportional to 1,121.28, 1,546.72 and 728.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,121.28 : 1,546.72 = 728.56 : x
2. Step 2: Convert to fraction form
   1,121.28/1,546.72 = 728.56/x
3. Step 3: Cross multiply
   1,121.28x = 1,546.72 × 728.56
4. Step 4: Simplify right side
   1,121.28x = 1,126,878.32
5. Step 5: Solve for x
   x = 1,126,878.32/1,121.28
6. Step 6: Final answer
   x = 1,004.99