Finding the Third Proportional to 181,290 and 398,428

Step by Step Solution

1. Step 1: Write the proportion equation
   181,290 : 398,428 = 398,428 : x
2. Step 2: Convert to fraction form
   181,290/398,428 = 398,428/x
3. Step 3: Cross multiply
   181,290x = 398,428 × 398,428
4. Step 4: Simplify right side
   181,290x = 158,744,871,184
5. Step 5: Solve for x
   x = 158,744,871,184/181,290
6. Step 6: Final answer
   x = 875,640.53