Finding the Fourth Proportional to 1,288.24, 1,777.55 and 728.62

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.24 : 1,777.55 = 728.62 : x
2. Step 2: Convert to fraction form
   1,288.24/1,777.55 = 728.62/x
3. Step 3: Cross multiply
   1,288.24x = 1,777.55 × 728.62
4. Step 4: Simplify right side
   1,288.24x = 1,295,150.39
5. Step 5: Solve for x
   x = 1,295,150.39/1,288.24
6. Step 6: Final answer
   x = 1,005.37