Finding the Third Proportional to 83.91 and 131.72

Step by Step Solution

1. Step 1: Write the proportion equation
   83.91 : 131.72 = 131.72 : x
2. Step 2: Convert to fraction form
   83.91/131.72 = 131.72/x
3. Step 3: Cross multiply
   83.91x = 131.72 × 131.72
4. Step 4: Simplify right side
   83.91x = 17,349.83
5. Step 5: Solve for x
   x = 17,349.83/83.91
6. Step 6: Final answer
   x = 206.78