Finding the Fourth Proportional to 1,409.83, 1,945.39 and 780.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,409.83 : 1,945.39 = 780.28 : x
2. Step 2: Convert to fraction form
   1,409.83/1,945.39 = 780.28/x
3. Step 3: Cross multiply
   1,409.83x = 1,945.39 × 780.28
4. Step 4: Simplify right side
   1,409.83x = 1,517,948.91
5. Step 5: Solve for x
   x = 1,517,948.91/1,409.83
6. Step 6: Final answer
   x = 1,076.69