Finding the Third Proportional to 311.25 and 607.50

Step by Step Solution

1. Step 1: Write the proportion equation
   311.25 : 607.50 = 607.50 : x
2. Step 2: Convert to fraction form
   311.25/607.50 = 607.50/x
3. Step 3: Cross multiply
   311.25x = 607.50 × 607.50
4. Step 4: Simplify right side
   311.25x = 369,056.25
5. Step 5: Solve for x
   x = 369,056.25/311.25
6. Step 6: Final answer
   x = 1,185.72