Finding the Third Proportional to 261,873 and 418,405.50

Step by Step Solution

1. Step 1: Write the proportion equation
   261,873 : 418,405.50 = 418,405.50 : x
2. Step 2: Convert to fraction form
   261,873/418,405.50 = 418,405.50/x
3. Step 3: Cross multiply
   261,873x = 418,405.50 × 418,405.50
4. Step 4: Simplify right side
   261,873x = 175,063,162,430.25
5. Step 5: Solve for x
   x = 175,063,162,430.25/261,873
6. Step 6: Final answer
   x = 668,504.06