Finding the Third Proportional to 64,400.50 and 139,890

Step by Step Solution

1. Step 1: Write the proportion equation
   64,400.50 : 139,890 = 139,890 : x
2. Step 2: Convert to fraction form
   64,400.50/139,890 = 139,890/x
3. Step 3: Cross multiply
   64,400.50x = 139,890 × 139,890
4. Step 4: Simplify right side
   64,400.50x = 19,569,212,100
5. Step 5: Solve for x
   x = 19,569,212,100/64,400.50
6. Step 6: Final answer
   x = 303,867.39