Finding the Fourth Proportional to 1,443.04, 1,991.40 and 779.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,443.04 : 1,991.40 = 779.89 : x
2. Step 2: Convert to fraction form
   1,443.04/1,991.40 = 779.89/x
3. Step 3: Cross multiply
   1,443.04x = 1,991.40 × 779.89
4. Step 4: Simplify right side
   1,443.04x = 1,553,072.95
5. Step 5: Solve for x
   x = 1,553,072.95/1,443.04
6. Step 6: Final answer
   x = 1,076.25