Finding the Fourth Proportional to 1,288.22, 1,777.94 and 728.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,288.22 : 1,777.94 = 728.89 : x
2. Step 2: Convert to fraction form
   1,288.22/1,777.94 = 728.89/x
3. Step 3: Cross multiply
   1,288.22x = 1,777.94 × 728.89
4. Step 4: Simplify right side
   1,288.22x = 1,295,922.69
5. Step 5: Solve for x
   x = 1,295,922.69/1,288.22
6. Step 6: Final answer
   x = 1,005.98