Finding the Third Proportional to 642,420 and 1,399,248

Step by Step Solution

1. Step 1: Write the proportion equation
   642,420 : 1,399,248 = 1,399,248 : x
2. Step 2: Convert to fraction form
   642,420/1,399,248 = 1,399,248/x
3. Step 3: Cross multiply
   642,420x = 1,399,248 × 1,399,248
4. Step 4: Simplify right side
   642,420x = 1,957,894,965,504
5. Step 5: Solve for x
   x = 1,957,894,965,504/642,420
6. Step 6: Final answer
   x = 3,047,686.82