Finding the Third Proportional to 142,407.75 and 311,414.25

Step by Step Solution

1. Step 1: Write the proportion equation
   142,407.75 : 311,414.25 = 311,414.25 : x
2. Step 2: Convert to fraction form
   142,407.75/311,414.25 = 311,414.25/x
3. Step 3: Cross multiply
   142,407.75x = 311,414.25 × 311,414.25
4. Step 4: Simplify right side
   142,407.75x = 96,978,835,103.06
5. Step 5: Solve for x
   x = 96,978,835,103.06/142,407.75
6. Step 6: Final answer
   x = 680,994.08