Finding the Fourth Proportional to 1,389.94, 1,918.22 and 866.04

Step by Step Solution

1. Step 1: Write the proportion equation
   1,389.94 : 1,918.22 = 866.04 : x
2. Step 2: Convert to fraction form
   1,389.94/1,918.22 = 866.04/x
3. Step 3: Cross multiply
   1,389.94x = 1,918.22 × 866.04
4. Step 4: Simplify right side
   1,389.94x = 1,661,255.25
5. Step 5: Solve for x
   x = 1,661,255.25/1,389.94
6. Step 6: Final answer
   x = 1,195.20