Finding the Third Proportional to 143,239 and 315,072

Step by Step Solution

1. Step 1: Write the proportion equation
   143,239 : 315,072 = 315,072 : x
2. Step 2: Convert to fraction form
   143,239/315,072 = 315,072/x
3. Step 3: Cross multiply
   143,239x = 315,072 × 315,072
4. Step 4: Simplify right side
   143,239x = 99,270,365,184
5. Step 5: Solve for x
   x = 99,270,365,184/143,239
6. Step 6: Final answer
   x = 693,040.06