Finding the Third Proportional to 389.94 and 857.38

Step by Step Solution

1. Step 1: Write the proportion equation
   389.94 : 857.38 = 857.38 : x
2. Step 2: Convert to fraction form
   389.94/857.38 = 857.38/x
3. Step 3: Cross multiply
   389.94x = 857.38 × 857.38
4. Step 4: Simplify right side
   389.94x = 735,091.89
5. Step 5: Solve for x
   x = 735,091.89/389.94
6. Step 6: Final answer
   x = 1,885.15