Finding the Third Proportional to 142,712 and 309,196

Step by Step Solution

1. Step 1: Write the proportion equation
   142,712 : 309,196 = 309,196 : x
2. Step 2: Convert to fraction form
   142,712/309,196 = 309,196/x
3. Step 3: Cross multiply
   142,712x = 309,196 × 309,196
4. Step 4: Simplify right side
   142,712x = 95,602,166,416
5. Step 5: Solve for x
   x = 95,602,166,416/142,712
6. Step 6: Final answer
   x = 669,895.78