Finding the Third Proportional to 139,287.75 and 300,742.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,287.75 : 300,742.50 = 300,742.50 : x
2. Step 2: Convert to fraction form
   139,287.75/300,742.50 = 300,742.50/x
3. Step 3: Cross multiply
   139,287.75x = 300,742.50 × 300,742.50
4. Step 4: Simplify right side
   139,287.75x = 90,446,051,306.25
5. Step 5: Solve for x
   x = 90,446,051,306.25/139,287.75
6. Step 6: Final answer
   x = 649,346.78