Finding the Fourth Proportional to 1,389.83, 1,917.59 and 865.94

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.83 : 1,917.59 = 865.94 : x
2. Step 2: Convert to fraction form
   1,389.83/1,917.59 = 865.94/x
3. Step 3: Cross multiply
   1,389.83x = 1,917.59 × 865.94
4. Step 4: Simplify right side
   1,389.83x = 1,660,503.97
5. Step 5: Solve for x
   x = 1,660,503.97/1,389.83
6. Step 6: Final answer
   x = 1,194.76