Finding the Fourth Proportional to 1,406.40, 1,940.86 and 776.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,406.40 : 1,940.86 = 776.96 : x
2. Step 2: Convert to fraction form
   1,406.40/1,940.86 = 776.96/x
3. Step 3: Cross multiply
   1,406.40x = 1,940.86 × 776.96
4. Step 4: Simplify right side
   1,406.40x = 1,507,970.59
5. Step 5: Solve for x
   x = 1,507,970.59/1,406.40
6. Step 6: Final answer
   x = 1,072.22