Finding the Third Proportional to 20.43 and 42.84

Step by Step Solution

1. Step 1: Write the proportion equation
   20.43 : 42.84 = 42.84 : x
2. Step 2: Convert to fraction form
   20.43/42.84 = 42.84/x
3. Step 3: Cross multiply
   20.43x = 42.84 × 42.84
4. Step 4: Simplify right side
   20.43x = 1,835.22
5. Step 5: Solve for x
   x = 1,835.22/20.43
6. Step 6: Final answer
   x = 89.82