Finding the Third Proportional to 414,300 and 639,765.75

Step by Step Solution

1. Step 1: Write the proportion equation
   414,300 : 639,765.75 = 639,765.75 : x
2. Step 2: Convert to fraction form
   414,300/639,765.75 = 639,765.75/x
3. Step 3: Cross multiply
   414,300x = 639,765.75 × 639,765.75
4. Step 4: Simplify right side
   414,300x = 409,300,214,873.06
5. Step 5: Solve for x
   x = 409,300,214,873.06/414,300
6. Step 6: Final answer
   x = 987,931.97