Finding the Fourth Proportional to 1,591.68, 2,388.60 and 861.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,591.68 : 2,388.60 = 861.34 : x
2. Step 2: Convert to fraction form
   1,591.68/2,388.60 = 861.34/x
3. Step 3: Cross multiply
   1,591.68x = 2,388.60 × 861.34
4. Step 4: Simplify right side
   1,591.68x = 2,057,396.72
5. Step 5: Solve for x
   x = 2,057,396.72/1,591.68
6. Step 6: Final answer
   x = 1,292.59