Finding the Third Proportional to 300,808.50 and 642,219

Step by Step Solution

1. Step 1: Write the proportion equation
   300,808.50 : 642,219 = 642,219 : x
2. Step 2: Convert to fraction form
   300,808.50/642,219 = 642,219/x
3. Step 3: Cross multiply
   300,808.50x = 642,219 × 642,219
4. Step 4: Simplify right side
   300,808.50x = 412,445,243,961
5. Step 5: Solve for x
   x = 412,445,243,961/300,808.50
6. Step 6: Final answer
   x = 1,371,122.31