Finding the Fourth Proportional to 1,369.05, 1,889.29 and 779.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.05 : 1,889.29 = 779.57 : x
2. Step 2: Convert to fraction form
   1,369.05/1,889.29 = 779.57/x
3. Step 3: Cross multiply
   1,369.05x = 1,889.29 × 779.57
4. Step 4: Simplify right side
   1,369.05x = 1,472,833.81
5. Step 5: Solve for x
   x = 1,472,833.81/1,369.05
6. Step 6: Final answer
   x = 1,075.81