Finding the Third Proportional to 309,070.69 and 641,818.69

Step by Step Solution

1. Step 1: Write the proportion equation
   309,070.69 : 641,818.69 = 641,818.69 : x
2. Step 2: Convert to fraction form
   309,070.69/641,818.69 = 641,818.69/x
3. Step 3: Cross multiply
   309,070.69x = 641,818.69 × 641,818.69
4. Step 4: Simplify right side
   309,070.69x = 411,931,227,624.22
5. Step 5: Solve for x
   x = 411,931,227,624.22/309,070.69
6. Step 6: Final answer
   x = 1,332,805.87