Finding the Third Proportional to 143,578 and 315,680

Step by Step Solution

1. Step 1: Write the proportion equation
   143,578 : 315,680 = 315,680 : x
2. Step 2: Convert to fraction form
   143,578/315,680 = 315,680/x
3. Step 3: Cross multiply
   143,578x = 315,680 × 315,680
4. Step 4: Simplify right side
   143,578x = 99,653,862,400
5. Step 5: Solve for x
   x = 99,653,862,400/143,578
6. Step 6: Final answer
   x = 694,074.74