Finding the Third Proportional to 138,420 and 213,853.50

Step by Step Solution

1. Step 1: Write the proportion equation
   138,420 : 213,853.50 = 213,853.50 : x
2. Step 2: Convert to fraction form
   138,420/213,853.50 = 213,853.50/x
3. Step 3: Cross multiply
   138,420x = 213,853.50 × 213,853.50
4. Step 4: Simplify right side
   138,420x = 45,733,319,462.25
5. Step 5: Solve for x
   x = 45,733,319,462.25/138,420
6. Step 6: Final answer
   x = 330,395.31