Finding the Third Proportional to 123.78 and 262.76

Step by Step Solution

1. Step 1: Write the proportion equation
   123.78 : 262.76 = 262.76 : x
2. Step 2: Convert to fraction form
   123.78/262.76 = 262.76/x
3. Step 3: Cross multiply
   123.78x = 262.76 × 262.76
4. Step 4: Simplify right side
   123.78x = 69,041.67
5. Step 5: Solve for x
   x = 69,041.67/123.78
6. Step 6: Final answer
   x = 557.78