Finding the Third Proportional to 648 and 1,042.50

Step by Step Solution

1. Step 1: Write the proportion equation
   648 : 1,042.50 = 1,042.50 : x
2. Step 2: Convert to fraction form
   648/1,042.50 = 1,042.50/x
3. Step 3: Cross multiply
   648x = 1,042.50 × 1,042.50
4. Step 4: Simplify right side
   648x = 1,086,806.25
5. Step 5: Solve for x
   x = 1,086,806.25/648
6. Step 6: Final answer
   x = 1,677.17