Finding the Third Proportional to 199,806 and 428,040

Step by Step Solution

1. Step 1: Write the proportion equation
   199,806 : 428,040 = 428,040 : x
2. Step 2: Convert to fraction form
   199,806/428,040 = 428,040/x
3. Step 3: Cross multiply
   199,806x = 428,040 × 428,040
4. Step 4: Simplify right side
   199,806x = 183,218,241,600
5. Step 5: Solve for x
   x = 183,218,241,600/199,806
6. Step 6: Final answer
   x = 916,980.68