Finding the Fourth Proportional to 1,379.43, 1,903.50 and 781.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.43 : 1,903.50 = 781.92 : x
2. Step 2: Convert to fraction form
   1,379.43/1,903.50 = 781.92/x
3. Step 3: Cross multiply
   1,379.43x = 1,903.50 × 781.92
4. Step 4: Simplify right side
   1,379.43x = 1,488,384.72
5. Step 5: Solve for x
   x = 1,488,384.72/1,379.43
6. Step 6: Final answer
   x = 1,078.99