Finding the Third Proportional to 261,790.50 and 420,018

Step by Step Solution

1. Step 1: Write the proportion equation
   261,790.50 : 420,018 = 420,018 : x
2. Step 2: Convert to fraction form
   261,790.50/420,018 = 420,018/x
3. Step 3: Cross multiply
   261,790.50x = 420,018 × 420,018
4. Step 4: Simplify right side
   261,790.50x = 176,415,120,324
5. Step 5: Solve for x
   x = 176,415,120,324/261,790.50
6. Step 6: Final answer
   x = 673,879.00