Finding the Fourth Proportional to 1,128.80, 1,557.83 and 731.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,128.80 : 1,557.83 = 731.03 : x
2. Step 2: Convert to fraction form
   1,128.80/1,557.83 = 731.03/x
3. Step 3: Cross multiply
   1,128.80x = 1,557.83 × 731.03
4. Step 4: Simplify right side
   1,128.80x = 1,138,814.50
5. Step 5: Solve for x
   x = 1,138,814.50/1,128.80
6. Step 6: Final answer
   x = 1,008.87