Finding the Fourth Proportional to 1,139.71, 1,572.51 and 697.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.71 : 1,572.51 = 697.45 : x
2. Step 2: Convert to fraction form
   1,139.71/1,572.51 = 697.45/x
3. Step 3: Cross multiply
   1,139.71x = 1,572.51 × 697.45
4. Step 4: Simplify right side
   1,139.71x = 1,096,747.10
5. Step 5: Solve for x
   x = 1,096,747.10/1,139.71
6. Step 6: Final answer
   x = 962.30