Finding the Third Proportional to 868.78 and 1,147.78

Step by Step Solution

1. Step 1: Write the proportion equation
   868.78 : 1,147.78 = 1,147.78 : x
2. Step 2: Convert to fraction form
   868.78/1,147.78 = 1,147.78/x
3. Step 3: Cross multiply
   868.78x = 1,147.78 × 1,147.78
4. Step 4: Simplify right side
   868.78x = 1,317,401.80
5. Step 5: Solve for x
   x = 1,317,401.80/868.78
6. Step 6: Final answer
   x = 1,516.38