Finding the Third Proportional to 245,617 and 390,569.50

Step by Step Solution

1. Step 1: Write the proportion equation
   245,617 : 390,569.50 = 390,569.50 : x
2. Step 2: Convert to fraction form
   245,617/390,569.50 = 390,569.50/x
3. Step 3: Cross multiply
   245,617x = 390,569.50 × 390,569.50
4. Step 4: Simplify right side
   245,617x = 152,544,534,330.25
5. Step 5: Solve for x
   x = 152,544,534,330.25/245,617
6. Step 6: Final answer
   x = 621,066.68