Finding the Third Proportional to 242,120 and 400,140

Step by Step Solution

1. Step 1: Write the proportion equation
   242,120 : 400,140 = 400,140 : x
2. Step 2: Convert to fraction form
   242,120/400,140 = 400,140/x
3. Step 3: Cross multiply
   242,120x = 400,140 × 400,140
4. Step 4: Simplify right side
   242,120x = 160,112,019,600
5. Step 5: Solve for x
   x = 160,112,019,600/242,120
6. Step 6: Final answer
   x = 661,292.00