Finding the Fourth Proportional to 1,369.40, 1,889.34 and 779.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,369.40 : 1,889.34 = 779.90 : x
2. Step 2: Convert to fraction form
   1,369.40/1,889.34 = 779.90/x
3. Step 3: Cross multiply
   1,369.40x = 1,889.34 × 779.90
4. Step 4: Simplify right side
   1,369.40x = 1,473,496.27
5. Step 5: Solve for x
   x = 1,473,496.27/1,369.40
6. Step 6: Final answer
   x = 1,076.02