Finding the Third Proportional to 680.50 and 1,085.50

Step by Step Solution

1. Step 1: Write the proportion equation
   680.50 : 1,085.50 = 1,085.50 : x
2. Step 2: Convert to fraction form
   680.50/1,085.50 = 1,085.50/x
3. Step 3: Cross multiply
   680.50x = 1,085.50 × 1,085.50
4. Step 4: Simplify right side
   680.50x = 1,178,310.25
5. Step 5: Solve for x
   x = 1,178,310.25/680.50
6. Step 6: Final answer
   x = 1,731.54