Finding the Fourth Proportional to 1,152.72, 1,728.95 and 765.09

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.72 : 1,728.95 = 765.09 : x
2. Step 2: Convert to fraction form
   1,152.72/1,728.95 = 765.09/x
3. Step 3: Cross multiply
   1,152.72x = 1,728.95 × 765.09
4. Step 4: Simplify right side
   1,152.72x = 1,322,798.53
5. Step 5: Solve for x
   x = 1,322,798.53/1,152.72
6. Step 6: Final answer
   x = 1,147.55