Finding the Third Proportional to 215,010 and 300,780

Step by Step Solution

1. Step 1: Write the proportion equation
   215,010 : 300,780 = 300,780 : x
2. Step 2: Convert to fraction form
   215,010/300,780 = 300,780/x
3. Step 3: Cross multiply
   215,010x = 300,780 × 300,780
4. Step 4: Simplify right side
   215,010x = 90,468,608,400
5. Step 5: Solve for x
   x = 90,468,608,400/215,010
6. Step 6: Final answer
   x = 420,764.65