Finding the Third Proportional to 57.69 and 85.69

Step by Step Solution

1. Step 1: Write the proportion equation
   57.69 : 85.69 = 85.69 : x
2. Step 2: Convert to fraction form
   57.69/85.69 = 85.69/x
3. Step 3: Cross multiply
   57.69x = 85.69 × 85.69
4. Step 4: Simplify right side
   57.69x = 7,343.35
5. Step 5: Solve for x
   x = 7,343.35/57.69
6. Step 6: Final answer
   x = 127.29