Finding the Fourth Proportional to 1,012.79, 1,397.12 and 717.54

Step by Step Solution

1. Step 1: Write the proportion equation
   1,012.79 : 1,397.12 = 717.54 : x
2. Step 2: Convert to fraction form
   1,012.79/1,397.12 = 717.54/x
3. Step 3: Cross multiply
   1,012.79x = 1,397.12 × 717.54
4. Step 4: Simplify right side
   1,012.79x = 1,002,485.90
5. Step 5: Solve for x
   x = 1,002,485.90/1,012.79
6. Step 6: Final answer
   x = 989.83