Finding the Third Proportional to 64,909.50 and 139,513.50

Step by Step Solution

1. Step 1: Write the proportion equation
   64,909.50 : 139,513.50 = 139,513.50 : x
2. Step 2: Convert to fraction form
   64,909.50/139,513.50 = 139,513.50/x
3. Step 3: Cross multiply
   64,909.50x = 139,513.50 × 139,513.50
4. Step 4: Simplify right side
   64,909.50x = 19,464,016,682.25
5. Step 5: Solve for x
   x = 19,464,016,682.25/64,909.50
6. Step 6: Final answer
   x = 299,863.91