Finding the Fourth Proportional to 1,478.59, 2,218.32 and 861.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,478.59 : 2,218.32 = 861.17 : x
2. Step 2: Convert to fraction form
   1,478.59/2,218.32 = 861.17/x
3. Step 3: Cross multiply
   1,478.59x = 2,218.32 × 861.17
4. Step 4: Simplify right side
   1,478.59x = 1,910,339.54
5. Step 5: Solve for x
   x = 1,910,339.54/1,478.59
6. Step 6: Final answer
   x = 1,292.00