Finding the Third Proportional to 414,875.50 and 640,740

Step by Step Solution

1. Step 1: Write the proportion equation
   414,875.50 : 640,740 = 640,740 : x
2. Step 2: Convert to fraction form
   414,875.50/640,740 = 640,740/x
3. Step 3: Cross multiply
   414,875.50x = 640,740 × 640,740
4. Step 4: Simplify right side
   414,875.50x = 410,547,747,600
5. Step 5: Solve for x
   x = 410,547,747,600/414,875.50
6. Step 6: Final answer
   x = 989,568.55