Finding the Third Proportional to 64,985 and 139,640

Step by Step Solution

1. Step 1: Write the proportion equation
   64,985 : 139,640 = 139,640 : x
2. Step 2: Convert to fraction form
   64,985/139,640 = 139,640/x
3. Step 3: Cross multiply
   64,985x = 139,640 × 139,640
4. Step 4: Simplify right side
   64,985x = 19,499,329,600
5. Step 5: Solve for x
   x = 19,499,329,600/64,985
6. Step 6: Final answer
   x = 300,058.93