Finding the Fourth Proportional to 1,380.69, 2,073.54 and 861.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,380.69 : 2,073.54 = 861.71 : x
2. Step 2: Convert to fraction form
   1,380.69/2,073.54 = 861.71/x
3. Step 3: Cross multiply
   1,380.69x = 2,073.54 × 861.71
4. Step 4: Simplify right side
   1,380.69x = 1,786,779.79
5. Step 5: Solve for x
   x = 1,786,779.79/1,380.69
6. Step 6: Final answer
   x = 1,294.12