Finding the Fourth Proportional to 1,139.36, 1,572.43 and 697.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.36 : 1,572.43 = 697.55 : x
2. Step 2: Convert to fraction form
   1,139.36/1,572.43 = 697.55/x
3. Step 3: Cross multiply
   1,139.36x = 1,572.43 × 697.55
4. Step 4: Simplify right side
   1,139.36x = 1,096,848.55
5. Step 5: Solve for x
   x = 1,096,848.55/1,139.36
6. Step 6: Final answer
   x = 962.69