Finding the Third Proportional to 142,776 and 212,499

Step by Step Solution

1. Step 1: Write the proportion equation
   142,776 : 212,499 = 212,499 : x
2. Step 2: Convert to fraction form
   142,776/212,499 = 212,499/x
3. Step 3: Cross multiply
   142,776x = 212,499 × 212,499
4. Step 4: Simplify right side
   142,776x = 45,155,825,001
5. Step 5: Solve for x
   x = 45,155,825,001/142,776
6. Step 6: Final answer
   x = 316,270.42