Finding the Third Proportional to 20,387 and 42,085

Step by Step Solution

1. Step 1: Write the proportion equation
   20,387 : 42,085 = 42,085 : x
2. Step 2: Convert to fraction form
   20,387/42,085 = 42,085/x
3. Step 3: Cross multiply
   20,387x = 42,085 × 42,085
4. Step 4: Simplify right side
   20,387x = 1,771,147,225
5. Step 5: Solve for x
   x = 1,771,147,225/20,387
6. Step 6: Final answer
   x = 86,876.30