Finding the Third Proportional to 15.28 and 40.78

Step by Step Solution

1. Step 1: Write the proportion equation
   15.28 : 40.78 = 40.78 : x
2. Step 2: Convert to fraction form
   15.28/40.78 = 40.78/x
3. Step 3: Cross multiply
   15.28x = 40.78 × 40.78
4. Step 4: Simplify right side
   15.28x = 1,663.11
5. Step 5: Solve for x
   x = 1,663.11/15.28
6. Step 6: Final answer
   x = 108.83