Finding the Fourth Proportional to 1,287.58, 1,777.15 and 728.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,287.58 : 1,777.15 = 728.37 : x
2. Step 2: Convert to fraction form
   1,287.58/1,777.15 = 728.37/x
3. Step 3: Cross multiply
   1,287.58x = 1,777.15 × 728.37
4. Step 4: Simplify right side
   1,287.58x = 1,294,419.10
5. Step 5: Solve for x
   x = 1,294,419.10/1,287.58
6. Step 6: Final answer
   x = 1,005.32