Finding the Fourth Proportional to 1,288.09, 1,777.82 and 728.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.09 : 1,777.82 = 728.56 : x
2. Step 2: Convert to fraction form
   1,288.09/1,777.82 = 728.56/x
3. Step 3: Cross multiply
   1,288.09x = 1,777.82 × 728.56
4. Step 4: Simplify right side
   1,288.09x = 1,295,248.54
5. Step 5: Solve for x
   x = 1,295,248.54/1,288.09
6. Step 6: Final answer
   x = 1,005.56