Finding the Third Proportional to 136,439 and 209,423.50

Step by Step Solution

1. Step 1: Write the proportion equation
   136,439 : 209,423.50 = 209,423.50 : x
2. Step 2: Convert to fraction form
   136,439/209,423.50 = 209,423.50/x
3. Step 3: Cross multiply
   136,439x = 209,423.50 × 209,423.50
4. Step 4: Simplify right side
   136,439x = 43,858,202,352.25
5. Step 5: Solve for x
   x = 43,858,202,352.25/136,439
6. Step 6: Final answer
   x = 321,449.16