Finding the Third Proportional to 111.50 and 131.75

Step by Step Solution

1. Step 1: Write the proportion equation
   111.50 : 131.75 = 131.75 : x
2. Step 2: Convert to fraction form
   111.50/131.75 = 131.75/x
3. Step 3: Cross multiply
   111.50x = 131.75 × 131.75
4. Step 4: Simplify right side
   111.50x = 17,358.06
5. Step 5: Solve for x
   x = 17,358.06/111.50
6. Step 6: Final answer
   x = 155.68