Finding the Third Proportional to 39.28 and 85.31

Step by Step Solution

1. Step 1: Write the proportion equation
   39.28 : 85.31 = 85.31 : x
2. Step 2: Convert to fraction form
   39.28/85.31 = 85.31/x
3. Step 3: Cross multiply
   39.28x = 85.31 × 85.31
4. Step 4: Simplify right side
   39.28x = 7,278.22
5. Step 5: Solve for x
   x = 7,278.22/39.28
6. Step 6: Final answer
   x = 185.28