Finding the Fourth Proportional to 42.56, 63.98 and 42.12

Step by Step Solution

1. Step 1: Write the proportion equation
   42.56 : 63.98 = 42.12 : x
2. Step 2: Convert to fraction form
   42.56/63.98 = 42.12/x
3. Step 3: Cross multiply
   42.56x = 63.98 × 42.12
4. Step 4: Simplify right side
   42.56x = 2,694.84
5. Step 5: Solve for x
   x = 2,694.84/42.56
6. Step 6: Final answer
   x = 63.32