Finding the Third Proportional to 245,615 and 390,566.50

Step by Step Solution

1. Step 1: Write the proportion equation
   245,615 : 390,566.50 = 390,566.50 : x
2. Step 2: Convert to fraction form
   245,615/390,566.50 = 390,566.50/x
3. Step 3: Cross multiply
   245,615x = 390,566.50 × 390,566.50
4. Step 4: Simplify right side
   245,615x = 152,542,190,922.25
5. Step 5: Solve for x
   x = 152,542,190,922.25/245,615
6. Step 6: Final answer
   x = 621,062.19