Finding the Fourth Proportional to 1,139.28, 1,706.49 and 1,111.74

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.28 : 1,706.49 = 1,111.74 : x
2. Step 2: Convert to fraction form
   1,139.28/1,706.49 = 1,111.74/x
3. Step 3: Cross multiply
   1,139.28x = 1,706.49 × 1,111.74
4. Step 4: Simplify right side
   1,139.28x = 1,897,173.19
5. Step 5: Solve for x
   x = 1,897,173.19/1,139.28
6. Step 6: Final answer
   x = 1,665.24