Finding the Third Proportional to 298,786.50 and 644,229

Step by Step Solution

1. Step 1: Write the proportion equation
   298,786.50 : 644,229 = 644,229 : x
2. Step 2: Convert to fraction form
   298,786.50/644,229 = 644,229/x
3. Step 3: Cross multiply
   298,786.50x = 644,229 × 644,229
4. Step 4: Simplify right side
   298,786.50x = 415,031,004,441
5. Step 5: Solve for x
   x = 415,031,004,441/298,786.50
6. Step 6: Final answer
   x = 1,389,055.41