Finding the Third Proportional to 266,646 and 428,110.50

Step by Step Solution

1. Step 1: Write the proportion equation
   266,646 : 428,110.50 = 428,110.50 : x
2. Step 2: Convert to fraction form
   266,646/428,110.50 = 428,110.50/x
3. Step 3: Cross multiply
   266,646x = 428,110.50 × 428,110.50
4. Step 4: Simplify right side
   266,646x = 183,278,600,210.25
5. Step 5: Solve for x
   x = 183,278,600,210.25/266,646
6. Step 6: Final answer
   x = 687,348.02