Finding the Third Proportional to 775.59 and 1,687.69

Step by Step Solution

1. Step 1: Write the proportion equation
   775.59 : 1,687.69 = 1,687.69 : x
2. Step 2: Convert to fraction form
   775.59/1,687.69 = 1,687.69/x
3. Step 3: Cross multiply
   775.59x = 1,687.69 × 1,687.69
4. Step 4: Simplify right side
   775.59x = 2,848,289.10
5. Step 5: Solve for x
   x = 2,848,289.10/775.59
6. Step 6: Final answer
   x = 3,672.40