Finding the Third Proportional to 64,778 and 139,492

Step by Step Solution

1. Step 1: Write the proportion equation
   64,778 : 139,492 = 139,492 : x
2. Step 2: Convert to fraction form
   64,778/139,492 = 139,492/x
3. Step 3: Cross multiply
   64,778x = 139,492 × 139,492
4. Step 4: Simplify right side
   64,778x = 19,458,018,064
5. Step 5: Solve for x
   x = 19,458,018,064/64,778
6. Step 6: Final answer
   x = 300,380.04