Finding the Third Proportional to 817.59 and 1,787.91

Step by Step Solution

1. Step 1: Write the proportion equation
   817.59 : 1,787.91 = 1,787.91 : x
2. Step 2: Convert to fraction form
   817.59/1,787.91 = 1,787.91/x
3. Step 3: Cross multiply
   817.59x = 1,787.91 × 1,787.91
4. Step 4: Simplify right side
   817.59x = 3,196,608.76
5. Step 5: Solve for x
   x = 3,196,608.76/817.59
6. Step 6: Final answer
   x = 3,909.78