Finding the Third Proportional to 243,222.75 and 390,799.69

Step by Step Solution

1. Step 1: Write the proportion equation
   243,222.75 : 390,799.69 = 390,799.69 : x
2. Step 2: Convert to fraction form
   243,222.75/390,799.69 = 390,799.69/x
3. Step 3: Cross multiply
   243,222.75x = 390,799.69 × 390,799.69
4. Step 4: Simplify right side
   243,222.75x = 152,724,395,750.10
5. Step 5: Solve for x
   x = 152,724,395,750.10/243,222.75
6. Step 6: Final answer
   x = 627,919.86