Finding the Third Proportional to 142,880 and 311,160

Step by Step Solution

1. Step 1: Write the proportion equation
   142,880 : 311,160 = 311,160 : x
2. Step 2: Convert to fraction form
   142,880/311,160 = 311,160/x
3. Step 3: Cross multiply
   142,880x = 311,160 × 311,160
4. Step 4: Simplify right side
   142,880x = 96,820,545,600
5. Step 5: Solve for x
   x = 96,820,545,600/142,880
6. Step 6: Final answer
   x = 677,635.40