Finding the Third Proportional to 393,988 and 870,920

Step by Step Solution

1. Step 1: Write the proportion equation
   393,988 : 870,920 = 870,920 : x
2. Step 2: Convert to fraction form
   393,988/870,920 = 870,920/x
3. Step 3: Cross multiply
   393,988x = 870,920 × 870,920
4. Step 4: Simplify right side
   393,988x = 758,501,646,400
5. Step 5: Solve for x
   x = 758,501,646,400/393,988
6. Step 6: Final answer
   x = 1,925,189.72