Finding the Third Proportional to 293,139.50 and 642,391.50

Step by Step Solution

1. Step 1: Write the proportion equation
   293,139.50 : 642,391.50 = 642,391.50 : x
2. Step 2: Convert to fraction form
   293,139.50/642,391.50 = 642,391.50/x
3. Step 3: Cross multiply
   293,139.50x = 642,391.50 × 642,391.50
4. Step 4: Simplify right side
   293,139.50x = 412,666,839,272.25
5. Step 5: Solve for x
   x = 412,666,839,272.25/293,139.50
6. Step 6: Final answer
   x = 1,407,749.00