Finding the Third Proportional to 61.70 and 90.18

Step by Step Solution

1. Step 1: Write the proportion equation
   61.70 : 90.18 = 90.18 : x
2. Step 2: Convert to fraction form
   61.70/90.18 = 90.18/x
3. Step 3: Cross multiply
   61.70x = 90.18 × 90.18
4. Step 4: Simplify right side
   61.70x = 8,131.67
5. Step 5: Solve for x
   x = 8,131.67/61.70
6. Step 6: Final answer
   x = 131.80