Finding the Third Proportional to 39,639.38 and 86,621.91

Step by Step Solution

1. Step 1: Write the proportion equation
   39,639.38 : 86,621.91 = 86,621.91 : x
2. Step 2: Convert to fraction form
   39,639.38/86,621.91 = 86,621.91/x
3. Step 3: Cross multiply
   39,639.38x = 86,621.91 × 86,621.91
4. Step 4: Simplify right side
   39,639.38x = 7,503,354,642.38
5. Step 5: Solve for x
   x = 7,503,354,642.38/39,639.38
6. Step 6: Final answer
   x = 189,290.44