Finding the Third Proportional to 59.80 and 90.81

Step by Step Solution

1. Step 1: Write the proportion equation
   59.80 : 90.81 = 90.81 : x
2. Step 2: Convert to fraction form
   59.80/90.81 = 90.81/x
3. Step 3: Cross multiply
   59.80x = 90.81 × 90.81
4. Step 4: Simplify right side
   59.80x = 8,246.20
5. Step 5: Solve for x
   x = 8,246.20/59.80
6. Step 6: Final answer
   x = 137.89