Finding the Third Proportional to 248,439 and 393,556.50

Step by Step Solution

1. Step 1: Write the proportion equation
   248,439 : 393,556.50 = 393,556.50 : x
2. Step 2: Convert to fraction form
   248,439/393,556.50 = 393,556.50/x
3. Step 3: Cross multiply
   248,439x = 393,556.50 × 393,556.50
4. Step 4: Simplify right side
   248,439x = 154,886,718,692.25
5. Step 5: Solve for x
   x = 154,886,718,692.25/248,439
6. Step 6: Final answer
   x = 623,439.63