Finding the Third Proportional to 243,147 and 390,667.50

Step by Step Solution

1. Step 1: Write the proportion equation
   243,147 : 390,667.50 = 390,667.50 : x
2. Step 2: Convert to fraction form
   243,147/390,667.50 = 390,667.50/x
3. Step 3: Cross multiply
   243,147x = 390,667.50 × 390,667.50
4. Step 4: Simplify right side
   243,147x = 152,621,095,556.25
5. Step 5: Solve for x
   x = 152,621,095,556.25/243,147
6. Step 6: Final answer
   x = 627,690.64