Finding the Third Proportional to 66.81 and 89.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66.81 : 89.50 = 89.50 : x
2. Step 2: Convert to fraction form
   66.81/89.50 = 89.50/x
3. Step 3: Cross multiply
   66.81x = 89.50 × 89.50
4. Step 4: Simplify right side
   66.81x = 8,010.25
5. Step 5: Solve for x
   x = 8,010.25/66.81
6. Step 6: Final answer
   x = 119.89