Finding the Fourth Proportional to 1,591.74, 2,389.10 and 861.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,591.74 : 2,389.10 = 861.89 : x
2. Step 2: Convert to fraction form
   1,591.74/2,389.10 = 861.89/x
3. Step 3: Cross multiply
   1,591.74x = 2,389.10 × 861.89
4. Step 4: Simplify right side
   1,591.74x = 2,059,141.40
5. Step 5: Solve for x
   x = 2,059,141.40/1,591.74
6. Step 6: Final answer
   x = 1,293.64