Finding the Fourth Proportional to 1,390.17, 1,919.03 and 866.46

Step by Step Solution

1. Step 1: Write the proportion equation
   1,390.17 : 1,919.03 = 866.46 : x
2. Step 2: Convert to fraction form
   1,390.17/1,919.03 = 866.46/x
3. Step 3: Cross multiply
   1,390.17x = 1,919.03 × 866.46
4. Step 4: Simplify right side
   1,390.17x = 1,662,758.40
5. Step 5: Solve for x
   x = 1,662,758.40/1,390.17
6. Step 6: Final answer
   x = 1,196.08