Finding the Third Proportional to 120,276 and 258,286.50

Step by Step Solution

1. Step 1: Write the proportion equation
   120,276 : 258,286.50 = 258,286.50 : x
2. Step 2: Convert to fraction form
   120,276/258,286.50 = 258,286.50/x
3. Step 3: Cross multiply
   120,276x = 258,286.50 × 258,286.50
4. Step 4: Simplify right side
   120,276x = 66,711,916,082.25
5. Step 5: Solve for x
   x = 66,711,916,082.25/120,276
6. Step 6: Final answer
   x = 554,656.92