Finding the Third Proportional to 123.89 and 265.78

Step by Step Solution

1. Step 1: Write the proportion equation
   123.89 : 265.78 = 265.78 : x
2. Step 2: Convert to fraction form
   123.89/265.78 = 265.78/x
3. Step 3: Cross multiply
   123.89x = 265.78 × 265.78
4. Step 4: Simplify right side
   123.89x = 70,639.67
5. Step 5: Solve for x
   x = 70,639.67/123.89
6. Step 6: Final answer
   x = 570.18