Finding the Third Proportional to 643,758 and 1,385,688

Step by Step Solution

1. Step 1: Write the proportion equation
   643,758 : 1,385,688 = 1,385,688 : x
2. Step 2: Convert to fraction form
   643,758/1,385,688 = 1,385,688/x
3. Step 3: Cross multiply
   643,758x = 1,385,688 × 1,385,688
4. Step 4: Simplify right side
   643,758x = 1,920,131,233,344
5. Step 5: Solve for x
   x = 1,920,131,233,344/643,758
6. Step 6: Final answer
   x = 2,982,691.06