Finding the Third Proportional to 90.70 and 131.20

Step by Step Solution

1. Step 1: Write the proportion equation
   90.70 : 131.20 = 131.20 : x
2. Step 2: Convert to fraction form
   90.70/131.20 = 131.20/x
3. Step 3: Cross multiply
   90.70x = 131.20 × 131.20
4. Step 4: Simplify right side
   90.70x = 17,214.26
5. Step 5: Solve for x
   x = 17,214.26/90.70
6. Step 6: Final answer
   x = 189.79