Finding the Fourth Proportional to 1,225.58, 1,690.83 and 728.12

Step by Step Solution

1. Step 1: Write the proportion equation
   1,225.58 : 1,690.83 = 728.12 : x
2. Step 2: Convert to fraction form
   1,225.58/1,690.83 = 728.12/x
3. Step 3: Cross multiply
   1,225.58x = 1,690.83 × 728.12
4. Step 4: Simplify right side
   1,225.58x = 1,231,127.14
5. Step 5: Solve for x
   x = 1,231,127.14/1,225.58
6. Step 6: Final answer
   x = 1,004.53