Finding the Third Proportional to 311,005 and 678,281.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311,005 : 678,281.50 = 678,281.50 : x
2. Step 2: Convert to fraction form
   311,005/678,281.50 = 678,281.50/x
3. Step 3: Cross multiply
   311,005x = 678,281.50 × 678,281.50
4. Step 4: Simplify right side
   311,005x = 460,065,793,242.25
5. Step 5: Solve for x
   x = 460,065,793,242.25/311,005
6. Step 6: Final answer
   x = 1,479,287.45