Finding the Third Proportional to 985.69 and 1,315.31

Step by Step Solution

1. Step 1: Write the proportion equation
   985.69 : 1,315.31 = 1,315.31 : x
2. Step 2: Convert to fraction form
   985.69/1,315.31 = 1,315.31/x
3. Step 3: Cross multiply
   985.69x = 1,315.31 × 1,315.31
4. Step 4: Simplify right side
   985.69x = 1,730,046.97
5. Step 5: Solve for x
   x = 1,730,046.97/985.69
6. Step 6: Final answer
   x = 1,755.17