Finding the Third Proportional to 438,619.50 and 661,170

Step by Step Solution

1. Step 1: Write the proportion equation
   438,619.50 : 661,170 = 661,170 : x
2. Step 2: Convert to fraction form
   438,619.50/661,170 = 661,170/x
3. Step 3: Cross multiply
   438,619.50x = 661,170 × 661,170
4. Step 4: Simplify right side
   438,619.50x = 437,145,768,900
5. Step 5: Solve for x
   x = 437,145,768,900/438,619.50
6. Step 6: Final answer
   x = 996,640.07