Finding the Third Proportional to 87,256 and 138,389.50

Step by Step Solution

1. Step 1: Write the proportion equation
   87,256 : 138,389.50 = 138,389.50 : x
2. Step 2: Convert to fraction form
   87,256/138,389.50 = 138,389.50/x
3. Step 3: Cross multiply
   87,256x = 138,389.50 × 138,389.50
4. Step 4: Simplify right side
   87,256x = 19,151,653,710.25
5. Step 5: Solve for x
   x = 19,151,653,710.25/87,256
6. Step 6: Final answer
   x = 219,488.10