Finding the Third Proportional to 288,146 and 422,870

Step by Step Solution

1. Step 1: Write the proportion equation
   288,146 : 422,870 = 422,870 : x
2. Step 2: Convert to fraction form
   288,146/422,870 = 422,870/x
3. Step 3: Cross multiply
   288,146x = 422,870 × 422,870
4. Step 4: Simplify right side
   288,146x = 178,819,036,900
5. Step 5: Solve for x
   x = 178,819,036,900/288,146
6. Step 6: Final answer
   x = 620,584.83