Finding the Third Proportional to 318,939 and 513,892.50

Step by Step Solution

1. Step 1: Write the proportion equation
   318,939 : 513,892.50 = 513,892.50 : x
2. Step 2: Convert to fraction form
   318,939/513,892.50 = 513,892.50/x
3. Step 3: Cross multiply
   318,939x = 513,892.50 × 513,892.50
4. Step 4: Simplify right side
   318,939x = 264,085,501,556.25
5. Step 5: Solve for x
   x = 264,085,501,556.25/318,939
6. Step 6: Final answer
   x = 828,012.57