Finding the Third Proportional to 64,878 and 139,576.50

Step by Step Solution

1. Step 1: Write the proportion equation
   64,878 : 139,576.50 = 139,576.50 : x
2. Step 2: Convert to fraction form
   64,878/139,576.50 = 139,576.50/x
3. Step 3: Cross multiply
   64,878x = 139,576.50 × 139,576.50
4. Step 4: Simplify right side
   64,878x = 19,481,599,352.25
5. Step 5: Solve for x
   x = 19,481,599,352.25/64,878
6. Step 6: Final answer
   x = 300,280.52