Finding the Third Proportional to 438,426 and 657,699.75

Step by Step Solution

1. Step 1: Write the proportion equation
   438,426 : 657,699.75 = 657,699.75 : x
2. Step 2: Convert to fraction form
   438,426/657,699.75 = 657,699.75/x
3. Step 3: Cross multiply
   438,426x = 657,699.75 × 657,699.75
4. Step 4: Simplify right side
   438,426x = 432,568,961,150.06
5. Step 5: Solve for x
   x = 432,568,961,150.06/438,426
6. Step 6: Final answer
   x = 986,640.76