Finding the Third Proportional to 215,100 and 300,870

Step by Step Solution

1. Step 1: Write the proportion equation
   215,100 : 300,870 = 300,870 : x
2. Step 2: Convert to fraction form
   215,100/300,870 = 300,870/x
3. Step 3: Cross multiply
   215,100x = 300,870 × 300,870
4. Step 4: Simplify right side
   215,100x = 90,522,756,900
5. Step 5: Solve for x
   x = 90,522,756,900/215,100
6. Step 6: Final answer
   x = 420,840.34