Finding the Fourth Proportional to 1,139.40, 1,706.40 and 1,116.18

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.40 : 1,706.40 = 1,116.18 : x
2. Step 2: Convert to fraction form
   1,139.40/1,706.40 = 1,116.18/x
3. Step 3: Cross multiply
   1,139.40x = 1,706.40 × 1,116.18
4. Step 4: Simplify right side
   1,139.40x = 1,904,649.55
5. Step 5: Solve for x
   x = 1,904,649.55/1,139.40
6. Step 6: Final answer
   x = 1,671.63