Finding the Third Proportional to 868.31 and 1,222.78

Step by Step Solution

1. Step 1: Write the proportion equation
   868.31 : 1,222.78 = 1,222.78 : x
2. Step 2: Convert to fraction form
   868.31/1,222.78 = 1,222.78/x
3. Step 3: Cross multiply
   868.31x = 1,222.78 × 1,222.78
4. Step 4: Simplify right side
   868.31x = 1,495,193.99
5. Step 5: Solve for x
   x = 1,495,193.99/868.31
6. Step 6: Final answer
   x = 1,721.95