Finding the Third Proportional to 345,639 and 718,868.50

Step by Step Solution

1. Step 1: Write the proportion equation
   345,639 : 718,868.50 = 718,868.50 : x
2. Step 2: Convert to fraction form
   345,639/718,868.50 = 718,868.50/x
3. Step 3: Cross multiply
   345,639x = 718,868.50 × 718,868.50
4. Step 4: Simplify right side
   345,639x = 516,771,920,292.25
5. Step 5: Solve for x
   x = 516,771,920,292.25/345,639
6. Step 6: Final answer
   x = 1,495,120.40