Finding the Third Proportional to 478,915.50 and 639,054

Step by Step Solution

1. Step 1: Write the proportion equation
   478,915.50 : 639,054 = 639,054 : x
2. Step 2: Convert to fraction form
   478,915.50/639,054 = 639,054/x
3. Step 3: Cross multiply
   478,915.50x = 639,054 × 639,054
4. Step 4: Simplify right side
   478,915.50x = 408,390,014,916
5. Step 5: Solve for x
   x = 408,390,014,916/478,915.50
6. Step 6: Final answer
   x = 852,739.19