Finding the Fourth Proportional to 1,139.46, 1,572.59 and 697.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.46 : 1,572.59 = 697.45 : x
2. Step 2: Convert to fraction form
   1,139.46/1,572.59 = 697.45/x
3. Step 3: Cross multiply
   1,139.46x = 1,572.59 × 697.45
4. Step 4: Simplify right side
   1,139.46x = 1,096,799.48
5. Step 5: Solve for x
   x = 1,096,799.48/1,139.46
6. Step 6: Final answer
   x = 962.56