Finding the Third Proportional to 140,142 and 209,709

Step by Step Solution

1. Step 1: Write the proportion equation
   140,142 : 209,709 = 209,709 : x
2. Step 2: Convert to fraction form
   140,142/209,709 = 209,709/x
3. Step 3: Cross multiply
   140,142x = 209,709 × 209,709
4. Step 4: Simplify right side
   140,142x = 43,977,864,681
5. Step 5: Solve for x
   x = 43,977,864,681/140,142
6. Step 6: Final answer
   x = 313,809.31