Finding the Fourth Proportional to 1,123.31, 1,685.84 and 779.06

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.31 : 1,685.84 = 779.06 : x
2. Step 2: Convert to fraction form
   1,123.31/1,685.84 = 779.06/x
3. Step 3: Cross multiply
   1,123.31x = 1,685.84 × 779.06
4. Step 4: Simplify right side
   1,123.31x = 1,313,370.83
5. Step 5: Solve for x
   x = 1,313,370.83/1,123.31
6. Step 6: Final answer
   x = 1,169.19