Finding the Third Proportional to 820 and 1,791.25

Step by Step Solution

1. Step 1: Write the proportion equation
   820 : 1,791.25 = 1,791.25 : x
2. Step 2: Convert to fraction form
   820/1,791.25 = 1,791.25/x
3. Step 3: Cross multiply
   820x = 1,791.25 × 1,791.25
4. Step 4: Simplify right side
   820x = 3,208,576.56
5. Step 5: Solve for x
   x = 3,208,576.56/820
6. Step 6: Final answer
   x = 3,912.90