Finding the Fourth Proportional to 42.28, 63.79 and 42.17

Step by Step Solution

1. Step 1: Write the proportion equation
   42.28 : 63.79 = 42.17 : x
2. Step 2: Convert to fraction form
   42.28/63.79 = 42.17/x
3. Step 3: Cross multiply
   42.28x = 63.79 × 42.17
4. Step 4: Simplify right side
   42.28x = 2,689.49
5. Step 5: Solve for x
   x = 2,689.49/42.28
6. Step 6: Final answer
   x = 63.61