Finding the Third Proportional to 298,028.50 and 638,670

Step by Step Solution

1. Step 1: Write the proportion equation
   298,028.50 : 638,670 = 638,670 : x
2. Step 2: Convert to fraction form
   298,028.50/638,670 = 638,670/x
3. Step 3: Cross multiply
   298,028.50x = 638,670 × 638,670
4. Step 4: Simplify right side
   298,028.50x = 407,899,368,900
5. Step 5: Solve for x
   x = 407,899,368,900/298,028.50
6. Step 6: Final answer
   x = 1,368,658.93