Finding the Third Proportional to 291,853.50 and 639,064.50

Step by Step Solution

1. Step 1: Write the proportion equation
   291,853.50 : 639,064.50 = 639,064.50 : x
2. Step 2: Convert to fraction form
   291,853.50/639,064.50 = 639,064.50/x
3. Step 3: Cross multiply
   291,853.50x = 639,064.50 × 639,064.50
4. Step 4: Simplify right side
   291,853.50x = 408,403,435,160.25
5. Step 5: Solve for x
   x = 408,403,435,160.25/291,853.50
6. Step 6: Final answer
   x = 1,399,343.97