Finding the Third Proportional to 760.78 and 1,021.78

Step by Step Solution

1. Step 1: Write the proportion equation
   760.78 : 1,021.78 = 1,021.78 : x
2. Step 2: Convert to fraction form
   760.78/1,021.78 = 1,021.78/x
3. Step 3: Cross multiply
   760.78x = 1,021.78 × 1,021.78
4. Step 4: Simplify right side
   760.78x = 1,044,036.92
5. Step 5: Solve for x
   x = 1,044,036.92/760.78
6. Step 6: Final answer
   x = 1,372.32