Finding the Third Proportional to 138,019.50 and 209,100

Step by Step Solution

1. Step 1: Write the proportion equation
   138,019.50 : 209,100 = 209,100 : x
2. Step 2: Convert to fraction form
   138,019.50/209,100 = 209,100/x
3. Step 3: Cross multiply
   138,019.50x = 209,100 × 209,100
4. Step 4: Simplify right side
   138,019.50x = 43,722,810,000
5. Step 5: Solve for x
   x = 43,722,810,000/138,019.50
6. Step 6: Final answer
   x = 316,787.19