Finding the Third Proportional to 139,865.50 and 210,959.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,865.50 : 210,959.50 = 210,959.50 : x
2. Step 2: Convert to fraction form
   139,865.50/210,959.50 = 210,959.50/x
3. Step 3: Cross multiply
   139,865.50x = 210,959.50 × 210,959.50
4. Step 4: Simplify right side
   139,865.50x = 44,503,910,640.25
5. Step 5: Solve for x
   x = 44,503,910,640.25/139,865.50
6. Step 6: Final answer
   x = 318,190.77