Finding the Third Proportional to 138,510 and 206,853.75

Step by Step Solution

1. Step 1: Write the proportion equation
   138,510 : 206,853.75 = 206,853.75 : x
2. Step 2: Convert to fraction form
   138,510/206,853.75 = 206,853.75/x
3. Step 3: Cross multiply
   138,510x = 206,853.75 × 206,853.75
4. Step 4: Simplify right side
   138,510x = 42,788,473,889.06
5. Step 5: Solve for x
   x = 42,788,473,889.06/138,510
6. Step 6: Final answer
   x = 308,919.75