Finding the Fourth Proportional to 1,132.72, 1,697.95 and 639.38

Step by Step Solution

1. Step 1: Write the proportion equation
   1,132.72 : 1,697.95 = 639.38 : x
2. Step 2: Convert to fraction form
   1,132.72/1,697.95 = 639.38/x
3. Step 3: Cross multiply
   1,132.72x = 1,697.95 × 639.38
4. Step 4: Simplify right side
   1,132.72x = 1,085,627.17
5. Step 5: Solve for x
   x = 1,085,627.17/1,132.72
6. Step 6: Final answer
   x = 958.43