Finding the Third Proportional to 139,840.50 and 209,758.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,840.50 : 209,758.50 = 209,758.50 : x
2. Step 2: Convert to fraction form
   139,840.50/209,758.50 = 209,758.50/x
3. Step 3: Cross multiply
   139,840.50x = 209,758.50 × 209,758.50
4. Step 4: Simplify right side
   139,840.50x = 43,998,628,322.25
5. Step 5: Solve for x
   x = 43,998,628,322.25/139,840.50
6. Step 6: Final answer
   x = 314,634.38