Finding the Third Proportional to 42.24 and 64.81

Step by Step Solution

1. Step 1: Write the proportion equation
   42.24 : 64.81 = 64.81 : x
2. Step 2: Convert to fraction form
   42.24/64.81 = 64.81/x
3. Step 3: Cross multiply
   42.24x = 64.81 × 64.81
4. Step 4: Simplify right side
   42.24x = 4,200.41
5. Step 5: Solve for x
   x = 4,200.41/42.24
6. Step 6: Final answer
   x = 99.44