Finding the Third Proportional to 308,128 and 646,064

Step by Step Solution

1. Step 1: Write the proportion equation
   308,128 : 646,064 = 646,064 : x
2. Step 2: Convert to fraction form
   308,128/646,064 = 646,064/x
3. Step 3: Cross multiply
   308,128x = 646,064 × 646,064
4. Step 4: Simplify right side
   308,128x = 417,398,692,096
5. Step 5: Solve for x
   x = 417,398,692,096/308,128
6. Step 6: Final answer
   x = 1,354,627.60