Finding the Third Proportional to 290,308.50 and 439,839

Step by Step Solution

1. Step 1: Write the proportion equation
   290,308.50 : 439,839 = 439,839 : x
2. Step 2: Convert to fraction form
   290,308.50/439,839 = 439,839/x
3. Step 3: Cross multiply
   290,308.50x = 439,839 × 439,839
4. Step 4: Simplify right side
   290,308.50x = 193,458,345,921
5. Step 5: Solve for x
   x = 193,458,345,921/290,308.50
6. Step 6: Final answer
   x = 666,388.84