Finding the Third Proportional to 685.88 and 1,061.63

Step by Step Solution

1. Step 1: Write the proportion equation
   685.88 : 1,061.63 = 1,061.63 : x
2. Step 2: Convert to fraction form
   685.88/1,061.63 = 1,061.63/x
3. Step 3: Cross multiply
   685.88x = 1,061.63 × 1,061.63
4. Step 4: Simplify right side
   685.88x = 1,127,047.64
5. Step 5: Solve for x
   x = 1,127,047.64/685.88
6. Step 6: Final answer
   x = 1,643.23