Finding the Third Proportional to 142,890 and 313,428

Step by Step Solution

1. Step 1: Write the proportion equation
   142,890 : 313,428 = 313,428 : x
2. Step 2: Convert to fraction form
   142,890/313,428 = 313,428/x
3. Step 3: Cross multiply
   142,890x = 313,428 × 313,428
4. Step 4: Simplify right side
   142,890x = 98,237,111,184
5. Step 5: Solve for x
   x = 98,237,111,184/142,890
6. Step 6: Final answer
   x = 687,501.65