Finding the Fourth Proportional to 1,139.61, 1,572.71 and 697.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.61 : 1,572.71 = 697.38 : x
2. Step 2: Convert to fraction form
   1,139.61/1,572.71 = 697.38/x
3. Step 3: Cross multiply
   1,139.61x = 1,572.71 × 697.38
4. Step 4: Simplify right side
   1,139.61x = 1,096,770.38
5. Step 5: Solve for x
   x = 1,096,770.38/1,139.61
6. Step 6: Final answer
   x = 962.41