Finding the Fourth Proportional to 42.20, 64.52 and 42.20

Step by Step Solution

1. Step 1: Write the proportion equation
   42.20 : 64.52 = 42.20 : x
2. Step 2: Convert to fraction form
   42.20/64.52 = 42.20/x
3. Step 3: Cross multiply
   42.20x = 64.52 × 42.20
4. Step 4: Simplify right side
   42.20x = 2,722.74
5. Step 5: Solve for x
   x = 2,722.74/42.20
6. Step 6: Final answer
   x = 64.52