Finding the Third Proportional to 638.50 and 875.50

Step by Step Solution

1. Step 1: Write the proportion equation
   638.50 : 875.50 = 875.50 : x
2. Step 2: Convert to fraction form
   638.50/875.50 = 875.50/x
3. Step 3: Cross multiply
   638.50x = 875.50 × 875.50
4. Step 4: Simplify right side
   638.50x = 766,500.25
5. Step 5: Solve for x
   x = 766,500.25/638.50
6. Step 6: Final answer
   x = 1,200.47