Finding the Fourth Proportional to 1,381.78, 1,906.77 and 760.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,381.78 : 1,906.77 = 760.78 : x
2. Step 2: Convert to fraction form
   1,381.78/1,906.77 = 760.78/x
3. Step 3: Cross multiply
   1,381.78x = 1,906.77 × 760.78
4. Step 4: Simplify right side
   1,381.78x = 1,450,632.48
5. Step 5: Solve for x
   x = 1,450,632.48/1,381.78
6. Step 6: Final answer
   x = 1,049.83