Finding the Third Proportional to 90.84 and 108.56

Step by Step Solution

1. Step 1: Write the proportion equation
   90.84 : 108.56 = 108.56 : x
2. Step 2: Convert to fraction form
   90.84/108.56 = 108.56/x
3. Step 3: Cross multiply
   90.84x = 108.56 × 108.56
4. Step 4: Simplify right side
   90.84x = 11,785.82
5. Step 5: Solve for x
   x = 11,785.82/90.84
6. Step 6: Final answer
   x = 129.74