Finding the Fourth Proportional to 1,288.23, 1,777.82 and 728.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.23 : 1,777.82 = 728.72 : x
2. Step 2: Convert to fraction form
   1,288.23/1,777.82 = 728.72/x
3. Step 3: Cross multiply
   1,288.23x = 1,777.82 × 728.72
4. Step 4: Simplify right side
   1,288.23x = 1,295,529.35
5. Step 5: Solve for x
   x = 1,295,529.35/1,288.23
6. Step 6: Final answer
   x = 1,005.67