Finding the Third Proportional to 3,920,640 and 8,317,128

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920,640 : 8,317,128 = 8,317,128 : x
2. Step 2: Convert to fraction form
   3,920,640/8,317,128 = 8,317,128/x
3. Step 3: Cross multiply
   3,920,640x = 8,317,128 × 8,317,128
4. Step 4: Simplify right side
   3,920,640x = 69,174,618,168,384
5. Step 5: Solve for x
   x = 69,174,618,168,384/3,920,640
6. Step 6: Final answer
   x = 17,643,705.66