Finding the Third Proportional to 139,173 and 310,219.50

Step by Step Solution

1. Step 1: Write the proportion equation
   139,173 : 310,219.50 = 310,219.50 : x
2. Step 2: Convert to fraction form
   139,173/310,219.50 = 310,219.50/x
3. Step 3: Cross multiply
   139,173x = 310,219.50 × 310,219.50
4. Step 4: Simplify right side
   139,173x = 96,236,138,180.25
5. Step 5: Solve for x
   x = 96,236,138,180.25/139,173
6. Step 6: Final answer
   x = 691,485.69