Finding the Third Proportional to 143,312 and 309,972

Step by Step Solution

1. Step 1: Write the proportion equation
   143,312 : 309,972 = 309,972 : x
2. Step 2: Convert to fraction form
   143,312/309,972 = 309,972/x
3. Step 3: Cross multiply
   143,312x = 309,972 × 309,972
4. Step 4: Simplify right side
   143,312x = 96,082,640,784
5. Step 5: Solve for x
   x = 96,082,640,784/143,312
6. Step 6: Final answer
   x = 670,443.79