Finding the Fourth Proportional to 1,139.30, 1,707.68 and 1,047.02

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.30 : 1,707.68 = 1,047.02 : x
2. Step 2: Convert to fraction form
   1,139.30/1,707.68 = 1,047.02/x
3. Step 3: Cross multiply
   1,139.30x = 1,707.68 × 1,047.02
4. Step 4: Simplify right side
   1,139.30x = 1,787,974.15
5. Step 5: Solve for x
   x = 1,787,974.15/1,139.30
6. Step 6: Final answer
   x = 1,569.37