Finding the Fourth Proportional to 1,399.52, 1,931.40 and 778.52

Step by Step Solution

1. Step 1: Write the proportion equation
   1,399.52 : 1,931.40 = 778.52 : x
2. Step 2: Convert to fraction form
   1,399.52/1,931.40 = 778.52/x
3. Step 3: Cross multiply
   1,399.52x = 1,931.40 × 778.52
4. Step 4: Simplify right side
   1,399.52x = 1,503,633.53
5. Step 5: Solve for x
   x = 1,503,633.53/1,399.52
6. Step 6: Final answer
   x = 1,074.39