Finding the Fourth Proportional to 1,139.16, 1,571.61 and 697.17

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.16 : 1,571.61 = 697.17 : x
2. Step 2: Convert to fraction form
   1,139.16/1,571.61 = 697.17/x
3. Step 3: Cross multiply
   1,139.16x = 1,571.61 × 697.17
4. Step 4: Simplify right side
   1,139.16x = 1,095,679.34
5. Step 5: Solve for x
   x = 1,095,679.34/1,139.16
6. Step 6: Final answer
   x = 961.83