Finding the Fourth Proportional to 1,039.78, 1,435.96 and 777.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,039.78 : 1,435.96 = 777.34 : x
2. Step 2: Convert to fraction form
   1,039.78/1,435.96 = 777.34/x
3. Step 3: Cross multiply
   1,039.78x = 1,435.96 × 777.34
4. Step 4: Simplify right side
   1,039.78x = 1,116,231.91
5. Step 5: Solve for x
   x = 1,116,231.91/1,039.78
6. Step 6: Final answer
   x = 1,073.53