Finding the Third Proportional to 138,568 and 210,040

Step by Step Solution

1. Step 1: Write the proportion equation
   138,568 : 210,040 = 210,040 : x
2. Step 2: Convert to fraction form
   138,568/210,040 = 210,040/x
3. Step 3: Cross multiply
   138,568x = 210,040 × 210,040
4. Step 4: Simplify right side
   138,568x = 44,116,801,600
5. Step 5: Solve for x
   x = 44,116,801,600/138,568
6. Step 6: Final answer
   x = 318,376.55