Finding the Third Proportional to 318,142.69 and 686,100.38

Step by Step Solution

1. Step 1: Write the proportion equation
   318,142.69 : 686,100.38 = 686,100.38 : x
2. Step 2: Convert to fraction form
   318,142.69/686,100.38 = 686,100.38/x
3. Step 3: Cross multiply
   318,142.69x = 686,100.38 × 686,100.38
4. Step 4: Simplify right side
   318,142.69x = 470,733,724,575.14
5. Step 5: Solve for x
   x = 470,733,724,575.14/318,142.69
6. Step 6: Final answer
   x = 1,479,630.82