Finding the Third Proportional to 105,120 and 215,145

Step by Step Solution

1. Step 1: Write the proportion equation
   105,120 : 215,145 = 215,145 : x
2. Step 2: Convert to fraction form
   105,120/215,145 = 215,145/x
3. Step 3: Cross multiply
   105,120x = 215,145 × 215,145
4. Step 4: Simplify right side
   105,120x = 46,287,371,025
5. Step 5: Solve for x
   x = 46,287,371,025/105,120
6. Step 6: Final answer
   x = 440,328.87