Finding the Fourth Proportional to 1,386.03, 1,912.72 and 765.03

Step by Step Solution

1. Step 1: Write the proportion equation
   1,386.03 : 1,912.72 = 765.03 : x
2. Step 2: Convert to fraction form
   1,386.03/1,912.72 = 765.03/x
3. Step 3: Cross multiply
   1,386.03x = 1,912.72 × 765.03
4. Step 4: Simplify right side
   1,386.03x = 1,463,288.18
5. Step 5: Solve for x
   x = 1,463,288.18/1,386.03
6. Step 6: Final answer
   x = 1,055.74