Finding the Fourth Proportional to 1,139.73, 1,572.37 and 696.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.73 : 1,572.37 = 696.86 : x
2. Step 2: Convert to fraction form
   1,139.73/1,572.37 = 696.86/x
3. Step 3: Cross multiply
   1,139.73x = 1,572.37 × 696.86
4. Step 4: Simplify right side
   1,139.73x = 1,095,721.76
5. Step 5: Solve for x
   x = 1,095,721.76/1,139.73
6. Step 6: Final answer
   x = 961.39